%%
%% The LaTeX Companion, 3ed
%%
%% Example 16-2-4 on page II-477 in "Customizing citation references and the bibliography in standard \LaTeX {}".
%%
%% 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{255.0pt}

% small headings for the example
\makeatletter
\renewcommand\section{\@startsection{section}{1}{\z@}%
                                    {-1.25ex \@plus-1ex \@minus-.2ex}%
                                    {.8ex}%
                                    {\normalsize\bfseries}}
%
% This example is one of the few that are slightly faked:
%
% Because we want to show the use of the openbib class option
% we pretend that this is what we call by showing a faked
% document class line that we gobble up with this:
%
\renewcommand\documentclass[2][]{}
%
% The work of the openbib option is to redefine \@openbib@code
% so we just do that manually here:
%
\renewcommand\@openbib@code{%
      \advance\leftmargin\bibindent
      \itemindent -\bibindent
      \listparindent \itemindent
      \parsep \z@
      }%
   \renewcommand\newblock{\par}
\makeatother

%StartShownPreambleCommands
\documentclass[openbib]{article}
\bibliographystyle{abbrv}
\setlength\bibindent{24pt}

\makeatletter
\renewcommand\@biblabel[1]
             {\textsuperscript{#1}}
\makeatother
%StopShownPreambleCommands

\begin{document}
\nocite{LWC99,Knuth:TB10-1-31}
\bibliography{tlc}
\end{document}