%% This is part of the OpTeX project, see http://petr.olsak.net/optex

\_codedecl \_undefined {BIB style (simple) <2023-09-13>} % loaded on demand by \usebib

\_ifx\_optexbibstyle\_undefined \_errmessage
   {This file can be read by: \_string\usebib/? (simple) bibfiles command only}
   \_endinput \_fi

% misc:

\_def\_maybedot{\_ifnum\_spacefactor=\_sfcode`\.\_relax\_else.\_fi}
\_tmpnum=\_sfcode`\. \_advance\_tmpnum by-2 \_sfcode`\.=\_tmpnum 
\_sfcode`\?=\_tmpnum \_sfcode`\!=\_tmpnum
\_let\:=\_maybedot  % prevents from double periods
\_ifx\.\_undefined \_let\.=\_maybedot \_fi % for backward compatibility

% Formatting of Author/Editor lists:

\_def\_authorname{%
  \_addauthlist
  \_ifnum\_NameCount>1
     \_ifnum0\_namecount=\_NameCount \_mtext{bib.and}\_else , \_fi
  \_fi
  \_bprintc\_Firstname{* }\_bprintc\_Von{* }\_Lastname\_bprintc\_Junior{, *}%
}
\_def\_addauthlist{%
   \_edef\_authlist{\_ifx\_authlist\_undefined \_else \_authlist;\_fi
                    \_Lastname,\_Firstname,\_Von,\_Junior}%
}
\_let\_editorname=\_authorname

% Preparing bib-mark (used when \nonumcitations is set):

\_def\_setbibmark{%
   \_ifx\_authlist\_undefined \_def\_authlist{,;}\_fi
   \_RetrieveFieldIn{bibmark}\_tmp      
   \_ifx\_tmp\_empty
      \_RetrieveFieldIn{year}\_tmp
      \_edef\_tmp{\_ea\_createbibmark\_expanded{\_tmp;\_authlist;,;,;,;}\_fin}\_fi
   \_bibmark=\_ea{\_tmp}%
}
\_def\_createbibmark#1;#2,#3\_fin{#2\_ifx^#1^\_else, #1\_fi}

\_def\_preurl{\_hfil\_break} 
\_def\_Inclause{In:~}

% Non-standard fieldnames:

\_CreateField {isbn}
\_CreateField {doi}
\_CreateField {url}
\_CreateField {bibmark}

% Sorting:

\_SortingOrder{name,year}{lfvj}
\_SpecialSort {key}

% Entry types:

\_sdef{_print:END}{%
   \_bprinta [note]       {*.}{}%
   \_setbibmark
}
\_sdef{_print:book}{%
   \_bprinta [!author]    {*.\ }{\_bibwarning}%
   \_bprintb [title]      {{\_em##1}\:\ }{\_bibwarning}%
   \_bprinta [edition]    {*\_mtext{bib.edition}\ }{}%
   \_bprinta [address]    {*: }{\_bibwarning}%
   \_bprinta [publisher]  {*, }{\_bibwarning}%
   \_bprinta [year]       {*.\ }{\_bibwarning}%
   \_bprinta [isbn]       {ISBN~*.\ }{\_bibwarning}%
   \_bprintb [url]        {\_preurl\_url{##1}. }{}%
}
\_sdef{_print:article}{%
   \_bprinta [!author]    {*.\ }{\_bibwarning}%
   \_bprinta [title]      {*\:\ }{\_bibwarning}%
   \_bprintb [journal]    {{\_em##1}\:\ }{\_bibwarning}%
   \_bprinta [year]       {*\_bprintv[volume,number,pages]{,}{.} }{}%
   \_bprinta [volume]     {* }{}%
   \_bprinta [number]     {(*)\_bprintv[pages]{,}{.} }{}%
   \_bprinta [pages]      {*.\ }{}%
   \_bprintb [doi]        {DOI~\_ulink[http://dx.doi.org/##1]{##1}.\ }{}%
}
\_sdef{_print:inbook}{%
   \_bprinta [!author]    {*.\ }{\_bibwarning}%
   \_bprintb [title]      {{\_em##1}\:\ }{\_bibwarning}%
                         \_Inclause
   \_let\_addauthlist\_relax   % no read authorlist again
   \_bprinta [!editor]    {*,~eds.\ }{}%
   \_bprintb [booktitle]  {{\_em##1}\:\ }{\_bibwarning}%
   \_bprinta [address]    {*: }{\_bibwarning}%
   \_bprinta [publisher]  {*, }{\_bibwarning}%
   \_bprinta [year]       {*.\ }{\_bibwarning}%
   \_bprinta [chapter]    {*.\ }{%
                         \_bprinta [pages]      {*.\ }{}}%
   \_bprinta [isbn]       {ISBN~*.\ }{}%
   \_bprintb [url]        {\_preurl\_url{##1}. }{}%
}
\_slet{_print:inproceedings}{_print:inbook}

\_sdef{_print:incollection}{%
   \_bprinta [!author]    {*.\ }{\_bibwarning}%
   \_bprintb [title]      {{\_em##1}\:\ }{\_bibwarning}%
   \_bprinta [crossreff]  {In~\_cite[*]. }{%
                         \_bprinta [booktitle]  {*. }{\_bibwarning}%
                         \_let\_addauthlist\_relax
                         \_bprinta [!editor]    {*,~eds.\ }{\_bibwarning}%
                         \_bprinta [edition]    {*\_mtext{bib.edition}\ }{\_bibwarning}%
                         \_bprinta [address]    {*: }{\_bibwarning}%
                         \_bprinta [publisher]  {*, }{\_bibwarning}%
                         \_bprinta [year]       {*.\ }{\_bibwarning}%
                         \_bprinta [pages]      {*.\ }{}%   
                         \_bprintb [url]        {\_preurl\_url{####1}. }{}}%
}
\_sdef{_print:conference}{%
   \_bprinta [!author]    {*.\ }{\_bibwarning}%
   \_bprintb [title]      {{\_em##1}\:\ }{\_bibwarning}%
   \_bprinta [edition]    {*\_mtext{bib.edition}\ }{}%
   \_bprinta [address]    {*: }{\_bibwarning}%
   \_bprinta [publisher]  {*, }{\_bibwarning}%
   \_bprinta [year]       {*.\ }{\_bibwarning}%
   \_bprinta [isbn]       {ISBN~*.\ }{}%
   \_bprintb [url]        {\_preurl\_url{##1}. }{}%
}
\_sdef{_print:thesis}{%
   \_bprinta [!author]    {*.\ }{\_bibwarning}%
   \_bprintb [title]      {{\_em##1}\:\ }{\_bibwarning}%
   \_bprinta [type]       {*,\ }{\_bibwarning}%
   \_bprinta [school]     {*.\ }{}%
   \_bprinta [address]    {*, }{}%
   \_bprinta [year]       {*.\ }{}%
   \_bprintb [url]        {\_preurl\_url{##1}. }{}%
}
\_sdef{_print:proceedings}{%
   \_bprinta [!author]    {*.\ }{\_bibwarning}%
   \_bprintb [title]      {{\_em##1}\:\ }{\_bibwarning}%
   \_bprinta [publisher]  {*.\ }{%
                         \_bprinta [organization] {*.\ }{\_bibwarning}}%
}   
\_sdef{_print:techreport}{%
   \_bprinta [!author]    {*.\ }{\_bibwarning}%
   \_bprintb [title]      {{\_em##1}\:\ }{\_bibwarning}%
                         \_mtext{bib.techreport}.
   \_bprinta [institution] {*.\ }{}%
}
\_sdef{_print:booklet}{%
   \_bprinta [!author]    {*.\ }{\_bibwarning}%
   \_bprintb [title]      {{\_em##1}\:\ }{\_bibwarning}%
   \_bprinta [howpublished] {*.\ }{\_bibwarning}%
}
\_sdef{_print:manual}{%
   \_bprinta [!author]    {*.\ }{}%
   \_bprintb [title]      {{\_em##1}\:\ }{\_bibwarning}%
   \_bprinta [year]       {*.\ }{}%
   \_bprinta [institution] {*.\ }{}%
   \_bprintb [url]        {\_preurl\_url{##1}. }{}%
}
\_sdef{_print:online}{%
   \_bprinta [!author]    {*.\ }{}%
   \_bprintb [title]      {{\_em##1}\:\ }{}%
   \_bprinta [howpublished] {*.\ }{}%
   \_bprinta [institution] {*.\ }{}%
   \_bprinta [series]     {*.\ }{}%
   \_bprintb [url]        {\_preurl\_url{##1}. }{\_bibwarning}%
}
\_sdef{_print:misc}{%
   \_bprinta [!author]    {*.\ }{}%
   \_bprintb [title]      {{\_em##1}\:\ }{}%
   \_bprinta [howpublished] {*.\ }{}%
   \_bprinta [institution] {*.\ }{}%
   \_bprinta [series]     {*.\ }{}%
   \_bprinta [year]       {*.\ }{}%
   \_bprintb [url]        {\_preurl\_url{##1}. }{}%
}

%%% end of the style file

\_endcode

You can copy this file to bib-yourname.opm and modify it by your
needs...