[Tex/LaTex] References / bibliography – English and German literature

biblatex

I use German as well as English literature in my work (written in German). Switching between "Vol."/ "Jg." and "No." /"Nr." in the bibliography works fine, but unfortunately there are some issues that I was not able to manage:

When I use \cite, \footcite and so on, the reference in my text / footnotes looks like this: e.g. "Beasley/Pagach/Warr (2008a, p. 10)" instead of "Beasley/Pagach/Warr (2008a, S. 10)"
Furthermore the date format in my English references is mm/dd/yyyy, but I prefer the dd.mm.yyyy format.

Last but not least there is something wrong with my line spacing in the bibliography. the spacing is sometimes too large – please have a look at the reference "Thommen/Achleitner (2012b)".

\documentclass[a4paper,bibliography=totoc,toc=listof,chapterentrydots=on,captions=tableheading,headings=small]{scrbook}
\usepackage[utf8]{inputenc}                 
\usepackage[T1]{fontenc}                    
\usepackage[ngerman,german,english]{babel}                                          
\usepackage{lmodern}                                                                
\usepackage[headsepline]{scrlayer-scrpage}                                          
\usepackage{microtype}                                                              
\usepackage{ragged2e}
\usepackage[format=hang,skip=2.5pt,justification=RaggedRight,singlelinecheck=false,labelfont=bf]{caption}
\usepackage{booktabs}
\usepackage{tabularx}
\usepackage{fp}
\usepackage{tikz}
\usepackage{xcolor}
\usepackage{etoolbox}

%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%

\usepackage[babel]{csquotes}
\usepackage[backend=biber,citetracker=true,autolang=other,style=authoryear,maxcitenames=2,maxbibnames=99,uniquename=false,uniquelist=true,isbn=false,doi=false]{biblatex}
\AtEveryCitekey{\ifciteseen{}{\defcounter{maxnames}{99}}}

%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%


% --- Backslash Authors --- %
\newcommand*{\citerevsdnamedelim}{} 
\newcommand*{\citemultinamedelim}{\slash} 
\newcommand*{\citefinalnamedelim}{\slash} 
\AtBeginDocument{%
 \let\revsdnamedelim\citerevsdnamedelim 
 \let\multinamedelim\citemultinamedelim% 
 \let\finalnamedelim\citefinalnamedelim% 
} 

% --- Semikolon --- % 
\renewcommand*{\multilistdelim}{\addsemicolon\space} 
\renewcommand*{\finallistdelim}{\addsemicolon\space} 


% --- () footnotes
% --- () year footnotes
\DeclareFieldFormat{bibhyperrefparens}{\bibhyperref{\mkbibparens{#1}}}

\newbibmacro*{cite:parens:labelyear+extrayear}{%
  \iffieldundef{labelyear}
    {}
    {\printtext[bibhyperrefparens]{%
       \printfield{labelyear}%
       \printfield{extrayear}}}}

\renewbibmacro*{cite}{%
  \iffieldundef{shorthand}
    {\ifthenelse{\ifnameundef{labelname}\OR\iffieldundef{labelyear}}
       {\usebibmacro{cite:label}%
        \setunit{\printdelim{nonameyeardelim}}}
       {\printnames{labelname}%
        \setunit{\printdelim{nameyeardelim}}}%
     \usebibmacro{cite:parens:labelyear+extrayear}}
    {\usebibmacro{cite:shorthand}}}


% --- authors footnotes / small caps text --- %
    \renewcommand*{\mkbibnamefamily}[1]{\textsc{#1}}

    \AtBeginBibliography{%
    \renewcommand*{\mkbibnamefamily}[1]{\textrm{#1}}}



%%%%%%%%%% MODIFICATION: BIBLIOGRAPY %%%%%%%%%%

% --- Sort authors --- % 
    \DeclareNameAlias{sortname}{last-first}

% --- colon after author and year --- % 
    \renewcommand{\labelnamepunct}{\addcolon\space} 

% --- No "-" for the same authors --- % 
    \ExecuteBibliographyOptions{dashed=false}        


% --- more space between references --- % 
    \setlength{\bibitemsep}{0.5\baselineskip} 


% - German vs. English literature - %
    \DefineBibliographyExtras{german}{
    \DeclareFieldFormat[article]{volume}{#1\adddot\addnbspace Jg\adddot\addcomma}   %Jg. Zeitschr. 
    \DeclareFieldFormat[article]{number}{\addspace Nr\adddot\addnbspace#1}          %Nr. Zeitschrift
    \DeclareFieldFormat{edition}{#1\adddot\addnbspace Aufl\adddot\addcomma}         %Auflage
    }

            \DefineBibliographyExtras{english}{
    \DeclareFieldFormat[article]{volume}{Vol\adddot\addnbspace #1\addcomma}         %Vol. Journal
    \DeclareFieldFormat[article]{number}{\addspace No\adddot\addnbspace#1}          %No. Journal
    \DeclareFieldFormat{edition}{#1\adddot\addnbspace Ed\adddot\addcomma}           %Edition
    }

    %\DeclareFieldFormat{pages}{S\adddot\addnbthinspace#1}                          %"S." for all units

% - title without quotation marks - %
    \DeclareFieldFormat[article]{title}{#1} 
    \DeclareFieldFormat[incollection]{title}{#1}
    \DeclareFieldFormat[thesis]{title}{#1}


% - No publisher - %
    \renewbibmacro*{publisher+location+date}{%
    \printlist{location}%
    \iflistundef{publisher}
    {\setunit*{\addcomma\space}}
    {\setunit*{\addcolon\space}}%
    %  \printlist{publisher}%
    \setunit*{\addcomma\space}%
    \usebibmacro{date}%
    \newunit}

% - URL - %
    \urlstyle{same}

    \DeclareFieldFormat{url}{\printtext{Unter\addcolon}\space\url{#1}}      % "URL" --> "Unter:"
    \DeclareFieldFormat{urldate}{\bibstring{urlseen}\space#1}               % date without brackets

    \DefineBibliographyStrings{german}{%                                    % "besucht am" --> "am"
    urlseen = {am}}
    \DefineBibliographyStrings{english}{%                                   % "besucht am" --> "am"
    urlseen = {am}}


%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
\bibliography{Master}
\usepackage{filecontents}
\begin{filecontents*}{Master.bib}

@article{Beasley.2008,
 author = {Beasley, Mark and Pagach, Don and Warr, Richard},
 year = {2008},
 title = {Information conveyed in hiring announcements of senior executives overseeing enterprise-wide risk management processes},
 pages = {311--332},
 pagination = {page},
 volume = {23},
 number = {55},
 journaltitle = {Journal of Accounting, Auditing {\&} Finance},
 abstract = {},
 hyphenation = {english},
 note = {}
}

@article{Beasley.2008b,
 author = {Beasley, Mark and Pagach, Don and Warr, Richard},
 year = {2008},
 title = {Information conveyed in hiring announcements of senior executives overseeing enterprise-wide risk management processes},
 pages = {311--332},
 pagination = {page},
 volume = {23},
 number = {55},
 journaltitle = {Journal of Accounting, Auditing {\&} Finance},
 abstract = {},
 hyphenation = {german},
 note = {}
}


@incollection{Wilderom.2000,
 author = {Wilderom, Celeste P. M. and Glunk, Ursula and Maslowski, Ralf},
 title = {Organizational culture as a predictor of organizational performance},
 pages = {193--209},
 bookpagination = {page},
 publisher = {SAGE},
 isbn = {1412973651},
 editor = {Ashkanasy, Neal M. and Wilderom, Celeste P. M. and Peterson, Mark F.},
 booktitle = {Handbook of organizational culture {\&} climate},
 year = {2000},
 abstract = {},
 hyphenation = {english}
}

@incollection{Wilderom.2000b,
 author = {Wilderom, Celeste P. M. and Glunk, Ursula and Maslowski, Ralf},
 title = {Organizational culture as a predictor of organizational performance},
 pages = {193--209},
 bookpagination = {page},
 publisher = {SAGE},
 isbn = {1412973651},
 editor = {Ashkanasy, Neal M. and Wilderom, Celeste P. M. and Peterson, Mark F.},
 booktitle = {Handbook of organizational culture {\&} climate},
 year = {2000},
 abstract = {},
 hyphenation = {german}
}

@book{Thommen.2012,
 author = {Thommen, Jean-Paul and Achleitner, Ann-Kristin},
 year = {2012},
 title = {Allgemeine Betriebswirtschaftslehre},
 edition = {7.},
 publisher = {{Gabler}},
 isbn = {9783834938442},
 subtitle = {Umfassende Einführung aus managementorientierter Sicht},
 hyphenation = {english},
 location = {Wiesbaden}
}

@book{Thommen.2012b,
 author = {Thommen, Jean-Paul and Achleitner, Ann-Kristin},
 year = {2012},
 title = {Allgemeine Betriebswirtschaftslehre},
 edition = {7.},
 publisher = {{Gabler}},
 isbn = {9783834938442},
 subtitle = {Umfassende Einführung aus managementorientierter Sicht},
 hyphenation = {german},
 location = {Wiesbaden}
}

@misc{Ashby.2012,
 author = {Ashby, Simon and Palermo, Tommaso and Power, Michael},
 year = {2012},
 title = {Risk culture in financial organisations: An interim report},
 url = {www.lse.ac.uk/accounting/CARR/pdf/risk-culture-interim-report.pdf},
 urldate = {2016-08-22},
 abstract = {},
 location = {London},
 organization = {{The London School of Economics and Political Science - Centre for Analysis of Risk and Regulation}},
 hyphenation = {english}
}

@misc{Ashby.2012b,
 author = {Ashby, Simon and Palermo, Tommaso and Power, Michael},
 year = {2012},
 title = {Risk culture in financial organisations: An interim report},
 url = {www.lse.ac.uk/accounting/CARR/pdf/risk-culture-interim-report.pdf},
 urldate = {2016-08-22},
 abstract = {},
 location = {London},
 organization = {{The London School of Economics and Political Science - Centre for Analysis of Risk and Regulation}},
 hyphenation = {german}
}

\end{filecontents*}

%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%

\begin{document}

\noindent
\textcites[][10]{Beasley.2008}[10]{Beasley.2008b}[11]{Wilderom.2000}[11]{Wilderom.2000b}[12]{Thommen.2012}[12]{Thommen.2012b}[13]{Ashby.2012}[13]{Ashby.2012b}
\printbibliography

\end{document}

I used the MWE for compiling the document (please find the screenshot attached below). Therefor I think there is an issue with one of the packages?! (I know this description is some kind of useless …)
I`ll try to post a new MWE tomorrow …

NEW MWE:

%%%% praeambel %%%%
\documentclass[a4paper,bibliography=totoc,toc=listof,chapterentrydots=on,captions=tableheading,headings=small]{scrbook}
\usepackage[utf8]{inputenc}                                                         
\usepackage[T1]{fontenc}
\usepackage[english,ngerman]{babel}                                         
\usepackage{lmodern}                                                                
\usepackage{scrlayer-scrpage}       
\usepackage{microtype}              
\usepackage{ragged2e}
\usepackage[format=hang,skip=2.5pt,justification=RaggedRight,singlelinecheck=false,labelfont=bf]{caption}
\usepackage{booktabs}
\usepackage{tabularx}
\usepackage[disable]{todonotes}
\usepackage{fp}
\usepackage{tikz}
\usepackage{xcolor}
\usetikzlibrary{positioning,shadings}
\usetikzlibrary{arrows.meta}
\usetikzlibrary{arrows}
\usetikzlibrary{shapes}
\usetikzlibrary{decorations.pathmorphing}
\usetikzlibrary{decorations.pathreplacing}
\usetikzlibrary{decorations.shapes}
\usetikzlibrary{decorations.text}
\usetikzlibrary{calc}
\usepackage{etoolbox}
\usepackage[printonlyused,withpage]{acronym}

\usepackage[babel]{csquotes}
\usepackage[language=autobib,backend=biber,citetracker=true,autolang=other,style=authoryear,maxcitenames=2,maxbibnames=99,uniquename=false,uniquelist=true,isbn=false,doi=false]{biblatex}

\AtEveryCitekey{\ifciteseen{}{\defcounter{maxnames}{99}}}

\renewcommand{\compcitedelim}{\space\bibstring{and}\space}

\renewcommand*{\revsdnamedelim}{} 
\renewcommand*{\multinamedelim}{\slash} 
\renewcommand*{\finalnamedelim}{\multinamedelim}

\renewcommand*{\multilistdelim}{\addsemicolon\space} 
\renewcommand*{\finallistdelim}{\multilistdelim} 



%%%% modifications %%%%
% --- indent footnotes ---%
\deffootnote{1em}{1em}{%
\textsuperscript{\thefootnotemark\ }}
\interfootnotelinepenalty=10000

% --- backslash autors references --- %
\newcommand*{\citerevsdnamedelim}{} 
\newcommand*{\citemultinamedelim}{\slash} 
\newcommand*{\citefinalnamedelim}{\slash} 
\AtBeginDocument{%
 \let\revsdnamedelim\citerevsdnamedelim 
 \let\multinamedelim\citemultinamedelim% 
 \let\finalnamedelim\citefinalnamedelim% 
} 

% --- semikolon references --- % 
\renewcommand*{\multilistdelim}{\addsemicolon\space} 
\renewcommand*{\finallistdelim}{\addsemicolon\space} 

% --- "u.a." --> "et al." --- %
\DefineBibliographyStrings{ngerman}{andothers={et\,al\adddot}}                  


% --- round brackets --> cite / footcite
\DeclareFieldFormat{bibhyperrefparens}{\bibhyperref{\mkbibparens{#1}}}

\newbibmacro*{cite:parens:labelyear+extrayear}{%
  \iffieldundef{labelyear}
    {}
    {\printtext[bibhyperrefparens]{%
       \printfield{labelyear}%
       \printfield{extrayear}}}}

\renewbibmacro*{cite}{%
  \iffieldundef{shorthand}
    {\ifthenelse{\ifnameundef{labelname}\OR\iffieldundef{labelyear}}
       {\usebibmacro{cite:label}%
        \setunit{\printdelim{nonameyeardelim}}}
       {\printnames{labelname}%
        \setunit{\printdelim{nameyeardelim}}}%
     \usebibmacro{cite:parens:labelyear+extrayear}}
    {\usebibmacro{cite:shorthand}}}


% --- authors small capital letters --- %
\renewcommand*{\mkbibnamefamily}[1]{\textsc{#1}}

\AtBeginBibliography{%
\renewcommand*{\mkbibnamefamily}[1]{\textrm{#1}}}


%% ====== Bibliography ====== %%                            
% --- spacing references --- % 
\setlength{\bibitemsep}{0.25\baselineskip}                          

% --- sort name author --- % 
\DeclareNameAlias{sortname}{last-first}

% --- ":" after author --- % 
\renewcommand{\labelnamepunct}{\addcolon\space}         

% --- title without quotation marks  --- % 
\DeclareFieldFormat[article]{title}{{#1}}                                   
\DeclareFieldFormat[book]{title}{{#1}}                              
\DeclareFieldFormat[incollection]{title}{{#1}}                          


% --- Englisch / German references --- %
%%% note: language --> hyphenation = {english} // hyphenation = {ngerman} %%%
\DefineBibliographyExtras{ngerman}{%
  \DeclareFieldFormat[article]{volume}{#1\adddot\addnbspace Jg\adddot\addcomma}%
  \DeclareFieldFormat[article]{number}{\addspace Nr\adddot\addnbspace#1}% 
  \DeclareFieldFormat{edition}{#1\adddot\addnbspace Aufl\adddot\addcomma}%
}

\DefineBibliographyExtras{english}{%
  \DeclareFieldFormat[article]{volume}{Vol\adddot\addnbspace #1\addcomma}%
  \DeclareFieldFormat[article]{number}{\addspace No\adddot\addnbspace#1}%
  \DeclareFieldFormat{edition}{#1\adddot\addnbspace Ed\adddot\addcomma}% 
}


% - no publisher - %
\renewbibmacro*{publisher+location+date}{%
  \printlist{location}%
  \iflistundef{publisher}
    {\setunit*{\addcomma\space}}
    {\setunit*{\addcolon\space}}%
  %\printlist{publisher}%
  \setunit*{\addcomma\space}%
  \usebibmacro{date}%
  \newunit}

%%%% - URL - %%%%
\urlstyle{same}

%\DeclareFieldFormat{url}{\printtext{Unter\addcolon}\space\url{#1}}          % "URL" --> "Unter:"
%\DeclareFieldFormat{urldate}{\bibstring{urlseen}\space#1}               % date without brackets

\DefineBibliographyStrings{ngerman}{%                                      % "besucht am" --> "zuletzt besucht am"
    urlseen = {zuletzt besucht am}}
\DefineBibliographyStrings{english}{%                                       % "besucht am" --> "zuletzt besucht am"
    urlseen = {zuletzt besucht am}}

% - chanching date from mm/dd/yyyy to dd.mm.yyyy -%
\DefineBibliographyExtras{english}{%
    \protected\def\mkbibordinal#1{\stripzeros{#1}\adddot}%
    \protected\def\mkbibmascord{\mkbibordinal}%
    \protected\def\mkbibfemord{\mkbibordinal}%
    \protected\def\mkbibneutord{\mkbibordinal}%
    \protected\def\mkbibdatelong#1#2#3{%
        \iffieldundef{#3}
        {}
        {\mkbibordinal{\thefield{#3}}%
        \iffieldundef{#2}{}{\nobreakspace}}%
        \iffieldundef{#2}
        {}
        {\mkbibmonth{\thefield{#2}}%
        \iffieldundef{#1}{}{\space}}%
        \iffieldbibstring{#1}{\bibstring{\thefield{#1}}}{\stripzeros{\thefield{#1}}}}%
    \protected\def\mkbibdateshort#1#2#3{%
        \iffieldundef{#3}
        {}
        {\mkdatezeros{\thefield{#3}}\adddot
        \iffieldundef{#2}{}{\thinspace}}%
        \iffieldundef{#2}
        {}
        {\mkdatezeros{\thefield{#2}}%
        \iffieldundef{#1}
             {}
            {\iffieldundef{#3}{/}{\adddot\thinspace}}}%
            \iffieldbibstring{#1}{\bibstring{\thefield{#1}}}{\mkdatezeros{\thefield{#1}}}}%
}




%%%% - bibliography - %%%%

\usepackage{filecontents}
\begin{filecontents*}{\jobname.bib}

@misc{BaselCommitteeonBankingSupervision.2015,
 author = {{BCBS}},
 year = {2015},
 title = {Title BCBS online document},
 url = {http://www.bis.org/filename.pdf},
 urldate = {2015-04-10},
 abstract = {},
 hyphenation = {ngerman},
 pagetotal = {55}
}

@misc{BaselCommitteeonBankingSupervision.2015e,
 author = {{BCBS}},
 year = {2015},
 title = {Title BCBS online document},
 url = {http://www.bis.org/filename.pdf},
 urldate = {2015-04-10},
 abstract = {},
 hyphenation = {english},
 pagetotal = {55}
}

@article{Sorensen.2002,
 author = {Sørensen, Jesper B. and Meier, Max X.},
 year = {2002},
 title = {Title Sørensen},
 keywords = {},
 pages = {70--91},
 pagination = {page},
 volume = {47},
 journaltitle = {English Journal},
 shortjournal = {},
 hyphenation = {english},
 issue = {1}
}

@article{Sathe.1983,
 author = {Sathe, Vijay},
 year = {1983},
 title = {Title Sathe},
 keywords = {},
 pages = {4--23},
 pagination = {page},
 volume = {12},
 issn = {00902616},
 journaltitle = {English Journal},
 hyphenation = {english},
 issue = {2}
}

@article{Schreyogg.1989,
 author = {Schreyögg, Georg},
 year = {1989},
 title = {Title Schreyögg},
 pages = {94--113},
 pagination = {page},
 volume = {41},
 journaltitle = {German Journal},
 hyphenation = {ngerman},
 issue = {2},
 abstract = {}
}

@incollection{Wilderom.2000e,
 author        = {Wilderom, Celeste P. M. and Glunk, Ursula and Maslowski, Ralf},
 title         = {Title in edited volume - English},
 pages         = {193--209},
 publisher     = {SAGE},
 isbn          = {1412973651},
 editor        = {Ashkanasy, Neal M. and Wilderom, Celeste P. M. and Peterson, Mark F.},
 booktitle     = {Edited volume - Englisch},
 year          = {2000},
 hyphenation   = {english}
}

@incollection{Wilderom.2000,
 author        = {Wilderom, Celeste P. M. and Glunk, Ursula and Maslowski, Ralf},
 title         = {Titel Beitrag Sammelband - Deutsch},
 pages         = {193--209},
 publisher     = {SAGE},
 isbn          = {1412973651},
 editor        = {Ashkanasy, Neal M. and Wilderom, Celeste P. M. and Peterson, Mark F.},
 booktitle     = {Sammelband - Deutsch},
 year          = {2000},
 hyphenation   = {ngerman}
}

\end{filecontents*}

\bibliography{\jobname}

%%%% text %%%%
\begin{document}

\textcite[][9]{BaselCommitteeonBankingSupervision.2015}

\textcite[][10]{BaselCommitteeonBankingSupervision.2015e}

Footnote I\footcite[Vgl.][11]{Schreyogg.1989}

Footnote II\footcites[Vgl.][12]{Sorensen.2002}[13]{Sathe.1983}

Footnote III\footcites[Vgl.][14]{Wilderom.2000}[15]{Wilderom.2000e}

Footnote IV\footcites[Vgl.][14]{Wilderom.2000}[15]{Wilderom.2000e}

\printbibliography

\end{document}

Best Answer

The setting

\usepackage[ngerman,german,english]{babel}

makes English the main language of your document (the last language is the main language), if you write in German, you want

\usepackage[german,english,ngerman]{babel}

(You could even drop german if you change all hyphenation = {german}s to ngerman - german is for pre-1996 orthography, ngerman is "neue Deutsche Rechtschreibung".)

Because the citations follow the main document language you get "p." instead of the German "S.".

The date format for English can be changed with

\DefineBibliographyExtras{english}{%
  \protected\def\mkbibordinal#1{\stripzeros{#1}\adddot}%
  \protected\def\mkbibmascord{\mkbibordinal}%
  \protected\def\mkbibfemord{\mkbibordinal}%
  \protected\def\mkbibneutord{\mkbibordinal}%
  \protected\def\mkbibdatelong#1#2#3{%
    \iffieldundef{#3}
      {}
      {\mkbibordinal{\thefield{#3}}%
       \iffieldundef{#2}{}{\nobreakspace}}%
    \iffieldundef{#2}
      {}
      {\mkbibmonth{\thefield{#2}}%
       \iffieldundef{#1}{}{\space}}%
    \iffieldbibstring{#1}{\bibstring{\thefield{#1}}}{\stripzeros{\thefield{#1}}}}%
  \protected\def\mkbibdateshort#1#2#3{%
    \iffieldundef{#3}
      {}
      {\mkdatezeros{\thefield{#3}}\adddot
       \iffieldundef{#2}{}{\thinspace}}%
    \iffieldundef{#2}
      {}
      {\mkdatezeros{\thefield{#2}}%
       \iffieldundef{#1}
         {}
         {\iffieldundef{#3}{/}{\adddot\thinspace}}}%
          \iffieldbibstring{#1}{\bibstring{\thefield{#1}}}{\mkdatezeros{\thefield{#1}}}}%
}

The extra space you are seeing is due to missing %s in \DefineBibliographyExtras, it should be

\DefineBibliographyExtras{german}{%
  \DeclareFieldFormat[article]{volume}{#1\adddot\addnbspace Jg\adddot\addcomma}%
  \DeclareFieldFormat[article]{number}{\addspace Nr\adddot\addnbspace#1}% 
  \DeclareFieldFormat{edition}{#1\adddot\addnbspace Aufl\adddot\addcomma}%
}

\DefineBibliographyExtras{english}{%
  \DeclareFieldFormat[article]{volume}{Vol\adddot\addnbspace #1\addcomma}%
  \DeclareFieldFormat[article]{number}{\addspace No\adddot\addnbspace#1}%
  \DeclareFieldFormat{edition}{#1\adddot\addnbspace Ed\adddot\addcomma}% 
}

See What is the use of percent signs (%) at the end of lines? for a bit of help on avoiding spurious whitespace.

This could probably better be done with proper use of the bibstring features, though I appreciate that the "Jg."/"Vol." thing is a bit complicated.

MWE

\documentclass{article}
\usepackage[utf8]{inputenc}                 
\usepackage[T1]{fontenc}                    
\usepackage[english,ngerman]{babel}                                          
\usepackage{lmodern}                                                                
\usepackage[babel]{csquotes}
\usepackage[language=autobib,backend=biber,citetracker=true,autolang=other,style=authoryear,maxcitenames=2,maxbibnames=99,uniquename=false,uniquelist=true,isbn=false,doi=false]{biblatex}
\AtEveryCitekey{\ifciteseen{}{\defcounter{maxnames}{99}}}

\renewcommand*{\revsdnamedelim}{} 
\renewcommand*{\multinamedelim}{\slash} 
\renewcommand*{\finalnamedelim}{\multinamedelim}

\renewcommand*{\multilistdelim}{\addsemicolon\space} 
\renewcommand*{\finallistdelim}{\multilistdelim} 


% --- () footnotes
% --- () year footnotes
\DeclareFieldFormat{bibhyperrefparens}{\bibhyperref{\mkbibparens{#1}}}

\newbibmacro*{cite:parens:labelyear+extrayear}{%
  \iffieldundef{labelyear}
    {}
    {\printtext[bibhyperrefparens]{%
       \printfield{labelyear}%
       \printfield{extrayear}}}}

\renewbibmacro*{cite}{%
  \iffieldundef{shorthand}
    {\ifthenelse{\ifnameundef{labelname}\OR\iffieldundef{labelyear}}
       {\usebibmacro{cite:label}%
        \setunit{\printdelim{nonameyeardelim}}}
       {\printnames{labelname}%
        \setunit{\printdelim{nameyeardelim}}}%
     \usebibmacro{cite:parens:labelyear+extrayear}}
    {\usebibmacro{cite:shorthand}}}


\renewcommand*{\mkbibnamefamily}[1]{\textsc{#1}}

\AtBeginBibliography{%
  \renewcommand*{\mkbibnamefamily}[1]{#1}}



%%%%%%%%%% MODIFICATION: BIBLIOGRAPY %%%%%%%%%%

% --- Sort authors --- % 
\DeclareNameAlias{sortname}{family-given}

% --- colon after author and year --- % 
\renewcommand{\labelnamepunct}{\addcolon\space} 

% --- No "-" for the same authors --- % 
\ExecuteBibliographyOptions{dashed=false}        


% --- more space between references --- % 
\setlength{\bibitemsep}{0.5\baselineskip} 


% - German vs. English literature - %
\DefineBibliographyExtras{german}{%
  \DeclareFieldFormat[article]{volume}{#1\adddot\addnbspace Jg\adddot\addcomma}%
  \DeclareFieldFormat[article]{number}{\addspace Nr\adddot\addnbspace#1}% 
  \DeclareFieldFormat{edition}{#1\adddot\addnbspace Aufl\adddot\addcomma}%
}

\DefineBibliographyExtras{english}{%
  \DeclareFieldFormat[article]{volume}{Vol\adddot\addnbspace #1\addcomma}%
  \DeclareFieldFormat[article]{number}{\addspace No\adddot\addnbspace#1}%
  \DeclareFieldFormat{edition}{#1\adddot\addnbspace Ed\adddot\addcomma}% 
}

% - title without quotation marks - 
\DeclareFieldFormat[article]{title}{#1} 
\DeclareFieldFormat[incollection]{title}{#1}
\DeclareFieldFormat[thesis]{title}{#1}


% - No publisher - %
\renewbibmacro*{publisher+location+date}{%
  \printlist{location}%
  \setunit*{\addcomma\space}%
  \usebibmacro{date}%
  \newunit}

% - URL - %
\urlstyle{same}

\DeclareFieldFormat{url}{\printtext{Unter\addcolon}\space\url{#1}} 
\DeclareFieldFormat{urldate}{\bibstring{urlseen}\space#1}          

\DefineBibliographyStrings{german}{%                               
  urlseen = {am}}
\DefineBibliographyStrings{english}{%                        
  urlseen = {am}}


\usepackage{filecontents}
\begin{filecontents*}{\jobname.bib}
@article{Beasley.2008,
 author       = {Beasley, Mark and Pagach, Don and Warr, Richard},
 year         = {2008},
 title        = {Information conveyed in hiring announcements of senior executives overseeing enterprise-wide risk management processes},
 pages        = {311--332},
 volume       = {23},
 number       = {55},
 journaltitle = {Journal of Accounting, Auditing {\&} Finance},
 hyphenation  = {english},
}

@article{Beasley.2008b,
 author       = {Beasley, Mark and Pagach, Don and Warr, Richard},
 year         = {2008},
 title        = {Information conveyed in hiring announcements of senior executives overseeing enterprise-wide risk management processes},
 pages        = {311--332},
 volume       = {23},
 number       = {55},
 journaltitle = {Journal of Accounting, Auditing {\&} Finance},
 hyphenation  = {ngerman},
}


@incollection{Wilderom.2000,
 author        = {Wilderom, Celeste P. M. and Glunk, Ursula and Maslowski, Ralf},
 title         = {Organizational culture as a predictor of organizational performance},
 pages         = {193--209},
 publisher     = {SAGE},
 isbn          = {1412973651},
 editor        = {Ashkanasy, Neal M. and Wilderom, Celeste P. M. and Peterson, Mark F.},
 booktitle     = {Handbook of organizational culture {\&} climate},
 year          = {2000},
 hyphenation   = {english}
}

@incollection{Wilderom.2000b,
 author        = {Wilderom, Celeste P. M. and Glunk, Ursula and Maslowski, Ralf},
 title         = {Organizational culture as a predictor of organizational performance},
 pages         = {193--209},
 publisher     = {SAGE},
 isbn          = {1412973651},
 editor        = {Ashkanasy, Neal M. and Wilderom, Celeste P. M. and Peterson, Mark F.},
 booktitle     = {Handbook of organizational culture {\&} climate},
 year          = {2000},
 hyphenation   = {ngerman}
}

@book{Thommen.2012,
 author      = {Thommen, Jean-Paul and Achleitner, Ann-Kristin},
 year        = {2012},
 title       = {Allgemeine Betriebswirtschaftslehre},
 edition     = {7},
 publisher   = {{Gabler}},
 isbn        = {9783834938442},
 subtitle    = {Umfassende Einführung aus managementorientierter Sicht},
 hyphenation = {english},
 location    = {Wiesbaden}
}

@book{Thommen.2012b,
 author      = {Thommen, Jean-Paul and Achleitner, Ann-Kristin},
 year        = {2012},
 title       = {Allgemeine Betriebswirtschaftslehre},
 edition     = {7},
 publisher   = {{Gabler}},
 isbn        = {9783834938442},
 subtitle    = {Umfassende Einführung aus managementorientierter Sicht},
 hyphenation = {ngerman},
 location    = {Wiesbaden}
}

@misc{Ashby.2012,
 author       = {Ashby, Simon and Palermo, Tommaso and Power, Michael},
 year         = {2012},
 title        = {Risk culture in financial organisations: An interim report},
 url          = {http://www.lse.ac.uk/accounting/CARR/pdf/risk-culture-interim-report.pdf},
 urldate      = {2016-08-22},
 location     = {London},
 organization = {{The London School of Economics and Political Science -- Centre for Analysis of Risk and Regulation}},
 hyphenation  = {english}
}

@misc{Ashby.2012b,
 author       = {Ashby, Simon and Palermo, Tommaso and Power, Michael},
 year         = {2012},
 title        = {Risk culture in financial organisations: An interim report},
 url          = {http://www.lse.ac.uk/accounting/CARR/pdf/risk-culture-interim-report.pdf},
 urldate      = {2016-08-22},
 location     = {London},
 organization = {{The London School of Economics and Political Science -- Centre for Analysis of Risk and Regulation}},
 hyphenation  = {ngerman}
}

\end{filecontents*}
\bibliography{\jobname}

%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%

\DefineBibliographyExtras{english}{%
  \protected\def\mkbibordinal#1{\stripzeros{#1}\adddot}%
  \protected\def\mkbibmascord{\mkbibordinal}%
  \protected\def\mkbibfemord{\mkbibordinal}%
  \protected\def\mkbibneutord{\mkbibordinal}%
  \protected\def\mkbibdatelong#1#2#3{%
    \iffieldundef{#3}
      {}
      {\mkbibordinal{\thefield{#3}}%
       \iffieldundef{#2}{}{\nobreakspace}}%
    \iffieldundef{#2}
      {}
      {\mkbibmonth{\thefield{#2}}%
       \iffieldundef{#1}{}{\space}}%
    \iffieldbibstring{#1}{\bibstring{\thefield{#1}}}{\stripzeros{\thefield{#1}}}}%
  \protected\def\mkbibdateshort#1#2#3{%
    \iffieldundef{#3}
      {}
      {\mkdatezeros{\thefield{#3}}\adddot
       \iffieldundef{#2}{}{\thinspace}}%
    \iffieldundef{#2}
      {}
      {\mkdatezeros{\thefield{#2}}%
       \iffieldundef{#1}
         {}
         {\iffieldundef{#3}{/}{\adddot\thinspace}}}%
          \iffieldbibstring{#1}{\bibstring{\thefield{#1}}}{\mkdatezeros{\thefield{#1}}}}%
}

\begin{document}

\noindent
\textcites[][10]{Beasley.2008}[10]{Beasley.2008b}[11]{Wilderom.2000}[11]{Wilderom.2000b}[12]{Thommen.2012}[12]{Thommen.2012b}[13]{Ashby.2012}[13]{Ashby.2012b}
\printbibliography

\end{document}

Please check the additional small changes I did to your code.

Postscript

As domwass notes, if you change your version of biblatex.bst in this way, you have to be aware that upgrades might break Biblatex if you use a local fork based on an older version. While most revisions don't introduce incompatible changes to biblatex.bst (there were no changes from 0.9e to 1.3 that would have caused problems, I think), the last revision, 1.4, introduced a very big change in the way biblatex.bst represented information in .bib files that certainly would have required creating a new patched file.

[Tex/LaTex] English / German APA reference fails partly – “retrieved from” and “origyear” untranslated

The bold "labels" tell you that bibstrings are not defined.

The reason that is happening is because the bibstrings for "retrieved from" and "origyear" are not defined in the "standard" language definition files (like ngerman.lbx), but by the APA style in ngerman-apa.lbx. You have mapped american to american-apa.lbx, but you haven't mapped ngerman to ngerman-apa.lbx -- so biblatex is looking for bibstrings in the default file and not finding them.

If you add the line

\DeclareLanguageMapping{ngerman}{ngerman-apa}

you get the strings you need. (I hesitated about this, because I thought I recalled some limitation on the number of such statements you could have; but I can't find that in the documentation, and it seems to work.)

Best Answer

Related Solutions

[Tex/LaTex] Biblatex and custom bibtex entries – is it possible

Postscript

[Tex/LaTex] English / German APA reference fails partly – “retrieved from” and “origyear” untranslated

Related Question