You should be loading the biblatex
package with the natbib
option, not the natbib
package:
\documentclass{article}
\usepackage[
backend=bibtex,
natbib=true,
bibstyle=verbose, citestyle=verbose, % bibstyle extensively modifed below
doi=true, url=true, % excluded from citations below
citecounter=true, citetracker=true,
block=space,
backref=true, backrefstyle=two,
abbreviate=false,
isbn=true
]{biblatex}
\addbibresource{\jobname.bib}
\begin{document}
\nocite{*}
\printbibliography
\end{document}
where the bib
file contains:
@Book{Armstrong:symmetry,
author = {Armstrong, M. A.},
title = {Groups and symmetry},
series = {Undergraduate Texts in Mathematics},
publisher = {Springer-Verlag},
address = {New York},
year = 1988,
pages = {xii+186},
isbn = {0-387-96675-7}
}
Also, in a user level document the correct command is \usepackage
not \RequirePackage
On the other hand, if you were really intending to use the natbib
package, then the syntax would be:
\documentclass{article}
\usepackage{natbib}
\begin{document}
\nocite{*}
\bibliographystyle{plainnat}
\bibliography{bibfile}
\end{document}
producing
with isbn included by default.
Best Answer
We have touched upon this subject before in Can I use a shortened “language” entry (language code) in my .bib file?, but let's make the distinction a bit more specific here.
The
biblatex
documentation says (on pp. 25-26)and (p. 20)
That means that the
langid
field holds the localisation you want to use for the entry in the bibliography (and citation depending on yourlanguage
option setting), it affects hyphenation patterns as well as localisation strings (the exact effect depends on the settings of thelanguage
andautolang
options). Because this is an internal directive forbiblatex
the information must be given in a form that TeX understands, you can usebabel
/polyglossia
language identifiers and with Biber even BCP47 language codes.If you want to prepare a multi-language bibliography, it is recommended to provide
langid
for all entries. Only with that information can LaTeX properly switch language environments and possibly fonts and encodings to avoid errors or unwanted output.The
language
list on the other hand has no special internal meaning, it just holds the language you want to see printed in the bibliography as the language of the work (in the standard styles the language is printed directly after the title, by default the optionclearlang
suppresses output of languages that match the document language).biblatex
offers some localisation support for this ("known" languages are listed in §4.9.2.18 Language Names), so you can either give the language "key" (russian
,langrussian
) in which casebiblatex
will translate the field for you, or you can give the content verbatim in case the language is not supported (Klingon
).As far as
biblatex
is concerned the two fields are completely independent. They do not influence each other. And you can have only one of the two fields filled, or both, or none – and the contents of the field need not be equivalent. You can, for example, haveWhich tells
biblatex
(mistakenly) to treat the work as German (new orthography) (langid = {ngerman}
), hyphenation and localisation strings will be changed accordingly (depending on yourlanguage
andautolang
options). However, since we havelanguage={french and latin}
"French and Latin" will be printed as the language(s) of the work. It would of course make no sense to give two languages aslangid
, but it may very well be that you want to convey the information that a work is bilingual French and Latin.In
we thus get
Note that even though the main language of the document is
british
, the information that the work is in French and Latin ("französisch und lateinisch",language={french and latin}
) is printed in German (langid={ngerman}
).