%%
%% The LaTeX Companion, 3ed
%%
%% Example 3-4-9 on page I-183 in "Changes, insertions, and deletions".
%%
%% 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{183.0pt}

%StartShownPreambleCommands
\usepackage[threshold=4]{csquotes}
%StopShownPreambleCommands

\begin{document}
He started his talk with the quotes
\blockquote[Umberto Eco][.]{Our life is full
  of empty  space}  and
\blockquote[Douglas Adams]{Space is big. You
  just  won't believe how vastly, hugely,
  mind-bogglingly big it is. I mean, you may
  think it's a long way down the road to the
  \textelp*{drug store}, but that's just peanuts
  to space \textelp{}}. Later on he finished with
\SetBlockThreshold{0}% -- force block quote
\blockquote[Albert  Einstein]{God does
  not play \textelp{}}.
\end{document}