%%
%% The LaTeX Companion, 3ed
%%
%% Example 3-4-13 on page I-186 in "Further configuration possibilities".
%%
%% 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{159.0pt}

  \setlength\leftmargini{1.5em} % -- shorten quote indentation for example

%StartShownPreambleCommands
\usepackage[threshold=1]{csquotes}
\renewcommand\mktextquote[6]
    {#1#2\ifblank{#4}{ \textelp{}}{#4}#5#3#6}
\renewcommand\mkblockquote[4]
    {\enquote{#1\ifblank{#2}{ \textelp{}}{#2}#3}#4}
%StopShownPreambleCommands

\begin{document}
He started 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}.
Later he finished with
\blockquote[Albert Einstein]{God does not play}.
\end{document}