[Tex/LaTex] Using multibib and natbib for French bibliographies

Question

I want two separate bibliographies in my work. I have used the package multibib to create my bibliography. The problem is that I am using natbib because my bibliography style requires it (francais.bst available here: ctan.org/pkg/francais-bst)

When I compile my file (for the first time with pdfLaTeX), I get this error

Here is my code:

\documentclass[11pt,a4paper]{article}
\setcounter{tocdepth}{4}
\setcounter{secnumdepth}{4}

\usepackage[francais]{babel}
\usepackage{multibib}
\newcites{B1}{Reference Book1}

\usepackage{natbib}
\bibliographystyle{francais}

\usepackage[utf8]{inputenc}
\usepackage[T1]{fontenc}
\usepackage{amsmath}
\usepackage{amsfonts}
\usepackage{amssymb}
\usepackage{graphicx}
\usepackage[left=1in,right=1in,top=1in,bottom=1in]{geometry}
\usepackage[defaultlines=3,all]{nowidow}


\pagenumbering{roman}

\begin{document}
The apples are green. \citepB1{ABF-19-35} Here there are!\citep{DEFQ-243}

\bibliographyB1{Book1}

\renewcommand{\refname}{Reference Book2}
\bibliography{Book2}

\end{document}

And my .bib files:
Book1:

@InBook{ABF-19-35,
  chapter   = {1:Qu'est-ce qui fait pousser la forêt},
  pages     = {19},
  title     = {Arbres et plantes forestières du Québec et des maritimes},
  publisher = {Éditions Michel Quintin},
  year      = {2007},
  author    = {Michel Leboeuf},
  editor    = {Johanne Ménard},
  note      = {ISBN: 978-2-89435-331-8},
}

Book2:

@InBook{DEFQ-243,
  chapter   = {Glossaire: description écologique des forêts du Québec},
  pages     = {243},
  title     = {Description écologique des forêts du Québec},
  publisher = {Centre collégial de développement de matériel didactique (CCDMD)},
  year      = {2007},
  author    = {Ph.D. Madeleine Couboue},
  note      = {ISBN: 978-2-89470-219-2},
}

If someone is able to help me with this to get something like this:

Answer 1

In general, TeX commands starting with letter cannot contain numbers. Hence in your case it is not the matter of 'natbib, but\citeB1and so on. In my example the stylealphasimulatesnatbib, as you can expect many problems with using it withmultibib. If you only need citations of the form(key), it might be a good simulation ofnatbib` behaviour.

\documentclass[11pt,a4paper]{article}
\setcounter{tocdepth}{4}
\setcounter{secnumdepth}{4}

\usepackage[francais]{babel}
\usepackage{multibib}
%\newcites{B1}{Reference Book1}
\newcites{B}{Reference Book1}

%\usepackage{natbib}
\bibliographystyle{francais}

\usepackage[utf8]{inputenc}
\usepackage[T1]{fontenc}
\usepackage{amsmath}
\usepackage{amsfonts}
\usepackage{amssymb}
\usepackage{graphicx}
\usepackage[left=1in,right=1in,top=1in,bottom=1in]{geometry}
\usepackage[defaultlines=3,all]{nowidow}


\pagenumbering{roman}

\begin{document}
\makeatletter
%\def\@cite#1#2{[{#1\if@tempswa , #2\fi}]}
\def\@cite#1#2{({#1\if@tempswa , #2\fi})} %square to rounded - PS
\makeatother

The apples are green. 
%\citepB1{ABF-19-35} Here there are!\citep{DEFQ-243}
\citeB{ABF-19-35} Here there are!\cite{DEFQ-243}

%\bibliographyB1{Book1}
\bibliographyB{Book1}
\bibliographystyleB{alpha}

\renewcommand{\refname}{Reference Book2}
\bibliography{Book2}

\end{document}