%%
%% The LaTeX Companion, 3ed
%%
%% Example 16-8-8 on page II-579 in "bibtopic --- Combining references by topic".
%%
%% Copyright (C) 2022 Frank Mittelbach
%%
%% It may be distributed and/or modified under the conditions
%% of the LaTeX Project Public License, either version 1.3c
%% of this license or (at your option) any later version.
%%
%% See https://www.latex-project.org/lppl.txt for details.
%%

\documentclass{tlc3exa}
\pagestyle{empty}
\setcounter{page}{6}
\setlength\textwidth{231.0pt}

% Use a special naming convention for aux files (for the book):
%
\AtBeginDocument{\renewcommand\thebtauxfile{\jobname+\arabic{btauxfile}}}
% Small headings for the example
\makeatletter
\renewcommand\section{\@startsection{section}{1}{\z@}%
                                    {-1.25ex \@plus-1ex \@minus-.2ex}%
                                    {.8ex}%
                                    {\normalsize\bfseries}}
\makeatother


% the two databases we use ...

\begin{filecontents*}[force]{tlc-tex.bib}
@Book{Knuth-CT-a,
  Author         = "Donald E. Knuth",
  Title          = "The {\TeX}book",
  Publisher      = "Ad{\-d}i{\-s}on-Wes{\-l}ey",
  Address        = "Reading, MA, USA",
  Volume         = "A",
  Series         = "Computers and Typesetting",
  pages          = "ix + 483",
  year           = 1986,
  isbn           = "0-201-13447-0",
}
\end{filecontents*}


\begin{filecontents*}[force]{tlc-jura.bib}
@BOOK{aschur,
  author     = {Hans Brox and Wolf-Dietrich Walker},
  title      = {Allgemeines Schuldrecht},
  language   = {ngerman},
  edition    = {29.},
  year       = 2003,
  address    = {M\"unchen}}

@BOOK{bschur,
  author     = {Hans Brox and Wolf-Dietrich Walker},
  title      = {Besonderes Schuldrecht},
  shorttitle = {BSchuR},
  language   = {ngerman},
  edition    = {27.},
  year       = 2002,
  address    = {M\"unchen}}
\end{filecontents*}

%StartShownPreambleCommands
\usepackage{bibtopic}
%StopShownPreambleCommands

\begin{document}
We saw the citations \cite{Knuth-CT-a},
\cite{aschur}, and \cite{bschur}.
\begin{btSect}{tlc-jura}
  \section*{Juridical literature}
  \btPrintCited
\end{btSect}
\begin{btSect}[abbrv]{tlc-tex}
  \section*{\TeX{} literature}
  \btPrintCited
\end{btSect}
\end{document}