%%
%% The LaTeX Companion, 3ed
%%
%% Example 16-1-3 on page II-472 in "Bibliographical reference schemes".
%%
%% 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{207.0pt}
% small headings for the example
  % Use biber program
  \makeatletter
  \renewcommand\section{\@startsection{section}{1}{\z@}%
    {-1.25ex \@plus-1ex \@minus-.2ex}%
    {.5ex}%
    {\normalfont\normalsize\bfseries}}
  \makeatother

%StartShownPreambleCommands

\usepackage[style=authoryear,
  uniquelist=false,maxnames=1]{biblatex}
\addbibresource{tlc.bib}
\addbibresource{tlc-ex.bib}
%StopShownPreambleCommands

\begin{document}
Entries with multiple authors might be
problematical, e.g., \cite{LGC97} and
\cite{test97} or even \cite{LGC97,test97}.
But then they might not.
\end{document}