%%
%% The LaTeX Companion, 2ed (second printing August 2004)
%%
%% Example 12-5-49 on page 744.
%%
%% Copyright (C) 2004 Frank Mittelbach, Michel Goossens,
%%    Johannes Braams, David Carlisle, and Chris Rowley
%%
%% It may be distributed and/or modified under the conditions
%% of the LaTeX Project Public License, either version 1.3
%% of this license or (at your option) any later version.
%%
%% See http://www.latex-project.org/lppl.txt for details.
%%

\documentclass{ttctexa}
\pagestyle{empty}
\setcounter{page}{6}
\setlength\textwidth{279.0pt}

\makeatletter
%Fix for overword.sty reported to Frank Bennett
\AtBeginDocument{\long\def\@ifowd{%
  \ifx\@let@token\@sptoken%
    \gdef\@preoverwordspace{ }%
    \let\reserved@e\@xifowd%
  \else%
    \gdef\@preoverwordspace{}%
    \ifx\@let@token\end%
      \let\reserved@e\reserved@d%
    \else%
      \ifx\@let@token\par%
        \let\reserved@e\@xifpargobble%
      \else%
        \long\def\reserved@e##1 {\long\gdef\@overword{##1}\@@ifowd}%
      \fi%
    \fi%
  \fi%
  \reserved@e}}

%Fix for camel.sty reported to Frank Bennett
\AtBeginDocument{\def\@realcite#1#2#3{%
  \ifcat$#1$\else%
   \setkeys{cameloptions}{#1}%             %<--- missing percent
  \fi%
  \if@law@requiresubjects%
   \@law@confirmsubject%
  \fi%
  \global\@ltok@argtwo{}%
  \ifcat$#3$\else%
    {\let\@law@parse=\@law@alparseplain\@law@parse #3,,}%
  \fi%
  {\let\@law@parse=\@law@clparseplain\@law@parse #2,,}%
  }}

\AtBeginDocument{\def\@printbibliography[#1]#2{%
  \global\@law@forcefootnotesfalse%
  \gdef\@law@temp{#1}\gdef\@law@temptwo{labels=false}%
  \let\camelrefname\refname%
  \expandafter\ifx\csname#2inputext\endcsname\relax%
    \global\@law@tablefalse%
  \else%
    \global\@law@tabletrue%
  \fi%
  \begingroup%
    \def\refname{\@law@getsubjectheader{#2}}%
      \@law@usepagesfalse%
      \@law@getbibformat{#2}%             %<--- missing percent
      \let\maybe\@gobble%
      \let\camelfill\relax%
      \let\camelarrow\relax%
  \ifx\@law@temp\@law@temptwo%
        \advance\@totalleftmargin -\labelsep%
        \advance\linewidth \labelsep%
        \def\@biblabel##1{}%
  \fi%
      \if@law@table%
        \if@law@usepages%
          \let\maybe\relax%
          \let\camelfill\dotfill%
          \let\camelarrow\rightarrow%
        \fi%
      \else%
        \longestlabelfor{#2}%
        \ifdim\lawlengthtwo=0pt%
          \advance\@totalleftmargin -\labelsep%
          \advance\linewidth \labelsep%
          \def\@biblabel##1{}%
        \fi%
      \fi%
    \if@law@requiresubjects%
      \@law@dobibliography{#2}%
    \else%
      \gdef\@law@temp{#2}\gdef\@law@temptwo{all}%
      \ifx\@law@temp\@law@temptwo%
        \@law@dobibliography{#2}%
      \else%
      \message{^^J===================================================^^J%
                  Camel bibliography ^^J
                   Document type: without-subjects ^^J
                   Bibliography type: subject-specific (#2) ^^J
                   Action: impossible task, ignoring ...^^J%
                  ===================================================^^J}% % missing percent
      \fi%
    \fi%
  \endgroup}}

% small headings for the example
\renewcommand\section{\@startsection{section}{1}{\z@}%
                                    {1.25ex \@plus1ex \@minus.2ex}%
                                    {.8ex}%
                                    {\normalsize\bfseries}}
\makeatother
\setlength\textheight{15\baselineskip}

\StartShownPreambleCommands
\usepackage{camel}
\citationsubject[o=tts,i=ttb]
     {tex}{\TeX{} literature}
\citationsubject[o=lts,i=ltb]
                {jur}{Law}
\forcefootnotes
\StopShownPreambleCommands
\begin{document}
\citationstyle{law}
\citationdata{jura,tex}

\ldots text
\source[a,s=tex]{Knuth-CT-a}
see-also \source[f,s=tex]
           {Knuth:TB10-1-31}
\ldots later\ldots
\source[t,s=jur]{bschur}
\printbibliography{jur}
\printbibliography{tex}
\end{document}