% BibTeX nearly standard bibliography style `iop' (one of the harvard family)
        % based on:
        % version 0.99a for BibTeX versions 0.99a or later, LaTeX version 2.09.
        % Copyright (C) 1984, 1985, 1988, 2010 Howard Trickey and Oren Patashnik.
        % Copyright (C) 1991, all rights reserved.
        % Unlimited copying and redistribution of this file are permitted as long as
        % (1) you make absolutely no changes to your copy, including name, or
        % (2) if you do make changes, you name it something other than
        % btxbst.doc, plain.bst, unsrt.bst, alpha.bst, abbrv.bst, agsm.bst,
        % dcu.bst, kluwer.bst or jphysicsB.bst.
        % This restriction helps ensure that all standard styles are identical.
        % The file harvard.tex has the documentation for this style.

% ACKNOWLEDGEMENT:
%   This document is a modified version of alpha.bst to which it owes much of
%   its functionality, and to which it inherits its free licensing.
%   The original copyright conditions allowing both unlimited copying
%   and redistribution can be found in the file 'alpha.bst' in CTAN distributions.

% AUTHORS:
% - EARLY:
% 
%   1984, 1985, 1988, 2010, Howard Trickey and Oren Patashnik.
% 
%   1991 Peter Williams, Key Centre for Design Quality, Sydney University
%   e-mail: peterw@archsci.arch.su.oz.au

% - LATER:
% Jan 2022 Boud Roukema: toggle alphabetical sorting on (2 lines ^SORT, ^SORT).
% October 2018 Boud Roukema: URL fix
% December 2011 Boud Roukema: as per below, but alphabetical sorting comment out (2 lines).
% May 2010 Boud Roukema: hacks similar to those of Antony Lewis added to jphysicsB.
%
% April 2006 Antony Lewis: added eprint, ADS and ISNB support
% See http://cosmocoffee.info/viewtopic.php?p=1567
% in tex file add
% \usepackage{hyperref}
% \bibliographystyle{apj_hyperref}
% \providecommand{\eprint}[1]{\href{http://arxiv.org/abs/#1}{#1}}
% \newcommand{\ISBN}[1]{\href{http://cosmologist.info/ISBN/#1}{ISBN: #1}}
% \providecommand{\adsurl}[1]{\href{#1}{ADS}}
%
% eprint number will be written after paper info, and arxiv, ADS and ISBN will be hyperlinked


ENTRY
  { address
    ISBN
    adsurl
    eprint
    author
    booktitle
    chapter
    edition
    editor
    howpublished
    institution
    journal
    key
    month
    note
    number
    organization
    pages
    publisher
    school
    series
    title
    type
    URL
    volume
    year
  }
  { field.used etal.allowed etal.required} %%%XXX change
  { extra.label sort.label list.year }

INTEGERS { output.state before.all mid.sentence after.sentence after.block }

FUNCTION {init.state.consts}
{ #0 'before.all :=
  #1 'mid.sentence :=
  #2 'after.sentence :=
  #3 'after.block :=
}

STRINGS { s t f }

FUNCTION {output.nonnull}
{ 's :=
  output.state mid.sentence =
    { " " * write$ }
    { output.state after.block =
        { add.period$ write$
          newline$
          "\newblock " write$
        }
        { output.state before.all =
            'write$
            { add.period$ " " * write$ }
          if$
        }
      if$
      mid.sentence 'output.state :=
    }
  if$
  s
}

FUNCTION {format.eprint}
{ eprint empty$
{ "" }
{ ", \eprint{" * eprint * "}" * }
if$
}
FUNCTION {format.adsurl}
{ adsurl empty$
{ "" }
%{  ", \href{" * adsurl * "}{ADS}" * }
%{  ", \adsurl{" * adsurl * "}" * }
{  "" * }  % 12.06.2006
%{  ", adsurl{" * "nothing" * "}" * }
if$
}
FUNCTION {format.ISBN}
{ ISBN empty$
{ "" }
%{ ", \href{http://cosmologist.info/ISBN/" * ISBN * "}{ISBN: " * ISBN * "}" * }
{ ", \ISBN{" * ISBN * "}" * }
if$
}





FUNCTION {output}
{ duplicate$ empty$
    'pop$
    'output.nonnull
  if$
}

FUNCTION {output.check}
{ 't :=
  duplicate$ empty$
    { pop$ "empty " t * " in " * cite$ * warning$ }
    'output.nonnull
  if$
}

FUNCTION {item.check}
{ 't :=
  empty$
    { "empty " t * " in " * cite$ * warning$ }
    { skip$ }
  if$
}

FUNCTION {fin.entry}
{ add.period$
  write$
  newline$
}

FUNCTION {new.block}
{ output.state before.all =
    'skip$
    { after.block 'output.state := }
  if$
}

FUNCTION {not}
{   { #0 }
    { #1 }
  if$
}

FUNCTION {and}
{   'skip$
    { pop$ #0 }
  if$
}

FUNCTION {or}
{   { pop$ #1 }
    'skip$
  if$
}

FUNCTION {field.or.null}
{ duplicate$ empty$
    { pop$ "" }
    'skip$
  if$
}

FUNCTION {emphasize}
{ duplicate$ empty$
    { pop$ "" }
    { "{\em " swap$ * "}" * }
  if$
}

FUNCTION {embolden}
{ duplicate$ empty$
    { pop$ "" }
    { "{\bf " swap$ * "}" * }
  if$
}

FUNCTION {quote}
{ duplicate$ empty$
    { pop$ "" }
    { "`" swap$ * "'" * }
  if$
}

FUNCTION {write.url}
{ URL empty$
    { skip$ }
    { "\newline\url{" URL * "}" * write$ newline$ }
  if$
}

INTEGERS { nameptr namesleft numnames }

FUNCTION {format.names}
{ 's :=
  'f :=
  #1 'nameptr :=
  s num.names$ 'numnames :=
  numnames 'namesleft :=
    { namesleft #0 > }
    { s nameptr f format.name$ 't :=
      nameptr #1 >
        { namesleft #1 >
            { ", " * t * }
            { t "others" =
                { " et~al." * }
                { " \harvardand\ " * t * }
              if$
            }
          if$
        }
        't
      if$
      nameptr #1 + 'nameptr :=
      namesleft #1 - 'namesleft :=
    }
  while$
}

FUNCTION {format.authors}
{ author empty$
    { "" }
    { "{vv~}{ll}{, jj}{ f{~}}" author format.names }
  if$
}

FUNCTION {format.editors}
{ editor empty$
    { "" }
    { "{vv~}{ll}{, jj}{ f{~}}" editor format.names
      editor num.names$ #1 >
        { ", eds" * }
        { ", ed." * }
      if$
    }
  if$
}

FUNCTION {format.editors.reverse}
{ editor empty$
    { "" }
    { "{f~}{vv~}{ll}{, jj}" editor format.names
      editor num.names$ #1 >
        { ", eds" * }
        { ", ed." * }
      if$
    }
  if$
}

FUNCTION {format.title}
{ title empty$
    { "" }
    { title "t" change.case$ }
  if$
}

FUNCTION {n.dashify}
{ 't :=
  ""
    { t empty$ not }
    { t #1 #1 substring$ "-" =
        { t #1 #2 substring$ "--" = not
            { "--" *
              t #2 global.max$ substring$ 't :=
            }
            {   { t #1 #1 substring$ "-" = }
                { "-" *
                  t #2 global.max$ substring$ 't :=
                }
              while$
            }
          if$
        }
        { t #1 #1 substring$ *
          t #2 global.max$ substring$ 't :=
        }
      if$
    }
  while$
}

FUNCTION {format.btitle}
{ title emphasize
}

FUNCTION {tie.or.space.connect}
{ duplicate$ text.length$ #3 <
    { "~" }
    { " " }
  if$
  swap$ * *
}

FUNCTION {either.or.check}
{ empty$
    'pop$
    { "can't use both " swap$ * " fields in " * cite$ * warning$ }
  if$
}

FUNCTION {format.bvolume}
{ volume empty$
    { "" }
    { "Vol." volume tie.or.space.connect
      series empty$
        'skip$
        { " of " * series emphasize * }
      if$
      "volume and number" number either.or.check
    }
  if$
}

FUNCTION {format.number.series}
{ volume empty$
    { number empty$
        { series field.or.null }
        { output.state mid.sentence =
            { "number" }
            { "Number" }
          if$
          number tie.or.space.connect
          series empty$
            { "there's a number but no series in " cite$ * warning$ }
            { " {\em in} " * series quote * }
          if$
        }
      if$
    }
    { "" }
  if$
}

FUNCTION {format.edition}
{ edition empty$
    { "" }
    { output.state mid.sentence =
        { edition "l" change.case$ " edn" * }
        { edition "t" change.case$ " edn" * }
      if$
    }
  if$
}

INTEGERS { multiresult }

FUNCTION {multi.page.check}
{ 't :=
  #0 'multiresult :=
    { multiresult not
      t empty$ not
      and
    }
    { t #1 #1 substring$
      duplicate$ "-" =
      swap$ duplicate$ "," =
      swap$ "+" =
      or or
        { #1 'multiresult := }
        { t #2 global.max$ substring$ 't := }
      if$
    }
  while$
  multiresult
}

FUNCTION {format.pages}
{ pages empty$
    { "" }
    { pages multi.page.check
        { "pp.~" pages n.dashify * }
        { "p.~" pages * }
      if$
    }
  if$
}

FUNCTION {format.vol.num.pages}
{ volume embolden field.or.null
  number empty$
    'skip$
    { "(" number * ")" * *
      volume empty$
        { "there's a number but no volume in " cite$ * warning$ }
        'skip$
      if$
    }
  if$
  pages empty$
    'skip$
    { duplicate$ empty$
        { pop$ format.pages }
        { ",~" * pages n.dashify * }
      if$
    }
  if$
}

FUNCTION {format.chapter.pages}
{ chapter empty$
    'format.pages
    { type empty$
        { "chapter" }
        { type "l" change.case$ }
      if$
      chapter tie.or.space.connect
      pages empty$
        'skip$
        { ", " * format.pages * }
      if$
    }
  if$
}

FUNCTION {format.in.ed.booktitle}
{ booktitle empty$
    { "" }
    { editor empty$
        { "{\em in} " booktitle quote * }
        { "{\em in} " format.editors.reverse * ", " * booktitle quote * }
      if$
    }
  if$
}

FUNCTION {empty.misc.check}
{ author empty$ title empty$ howpublished empty$
  month empty$ year empty$ note empty$
  and and and and and
  key empty$ not and
    { "all relevant fields are empty in " cite$ * warning$ }
    'skip$
  if$
}

FUNCTION {format.thesis.type}
{ type empty$
    'skip$
    { pop$
      type "t" change.case$
    }
  if$
}

FUNCTION {format.tr.number}
{ type empty$
    { "Technical Report" }
    'type
  if$
  number empty$
    { "t" change.case$ }
    { number tie.or.space.connect }
  if$
}

FUNCTION {format.article.crossref}
{ key empty$
    { journal empty$
        { "need key or journal for " cite$ * " to crossref " * crossref *
          warning$
          ""
        }
        { "in {\em " journal * "\/} \cite{" * crossref * "}" *}
      if$
    }
    { "{\em in} \citeasnoun{" crossref * "}" * }
  if$

}

FUNCTION {format.book.crossref}
{ volume empty$
    { "empty volume in " cite$ * "'s crossref of " * crossref * warning$
      "in "
    }
    { "Vol." volume tie.or.space.connect
      " of " *
    }
  if$
  editor empty$
  editor field.or.null author field.or.null =
  or
    { key empty$
        { series empty$
            { "need editor, key, or series for " cite$ * " to crossref " *
              crossref * warning$
              "" *
            }
            { "{\em " * series * "\/} \cite{" * crossref * "}" *}
          if$
        }
        { " \citeasnoun{" * crossref * "}" * }
      if$
    }
    { " \citeasnoun{" * crossref * "}" * }
  if$
}

FUNCTION {format.incoll.inproc.crossref}
{ editor empty$
  editor field.or.null author field.or.null =
  or
    { key empty$
        { booktitle empty$
            { "need editor, key, or booktitle for " cite$ * " to crossref " *
              crossref * warning$
              ""
            }
            { "in {\em " booktitle * "\/}" * " \cite{" * crossref * "}" *}
          if$
        }
        { "{\em in} \citeasnoun{" crossref * "}" * }
      if$
    }
    { "{\em in} \citeasnoun{" crossref * "}" * }
  if$

}

INTEGERS { len }

FUNCTION {chop.word}
{ 's :=
  'len :=
  s #1 len substring$ =
    { s len #1 + global.max$ substring$ }
    's
  if$
}

INTEGERS { ind tsslen }

STRINGS { tss ret rss istr }

FUNCTION {replace.substring}{
  'rss :=
  'tss :=
  'istr :=
  "" 'ret :=
  tss text.length$ 'tsslen :=
  #1 'ind :=
    { istr ind tsslen substring$ "" = not }
    { istr ind tsslen substring$ tss =
        { ret rss * 'ret :=
          ind tsslen + 'ind :=
        }
        { ret istr ind #1 substring$ * 'ret :=
          ind #1 + 'ind :=
        }
      if$
    }
  while$
  ret
}

FUNCTION {format.lab.names.abbr}
{ 's :=
  s num.names$ 'numnames :=
  numnames #1 >
    { numnames #2 >
        { s #1 "{vv~}{ll}" format.name$ " et~al." * }
        { s #2 "{ff }{vv }{ll}{ jj}" format.name$ "others" =
            { s #1 "{vv~}{ll}" format.name$ " et~al." * }
            { s #1 "{vv~}{ll}" format.name$ " \harvardand\ " *
              s #2 "{vv~}{ll}" format.name$ *
            }
          if$
        }
      if$
    }
    { s #1 "{vv~}{ll}" format.name$ }
  if$
}

FUNCTION {format.lab.names.full}
{ 's :=
  #1 'nameptr :=
  s num.names$ 'numnames :=
  numnames 'namesleft :=
    { namesleft #0 > }
    { s nameptr "{vv~}{ll}" format.name$ 't :=
      nameptr #1 >
        { namesleft #1 >
            { ", " * t * }
            { t "others" =
                { " et~al." * }
                { " \harvardand\ " * t * }
              if$
            }
          if$
        }
        't
      if$
      nameptr #1 + 'nameptr :=
      namesleft #1 - 'namesleft :=
    }
  while$
}

INTEGERS { author.field editor.field organization.field title.field key.field }

FUNCTION {init.field.constants}
{ #0 'author.field :=
  #1 'editor.field :=
  #2 'organization.field :=
  #3 'title.field :=
  #4 'key.field :=
}

FUNCTION {make.list.label}
{ author.field field.used =
    { format.authors }
    { editor.field field.used =
        { format.editors }
        { organization.field field.used =
            { "The " #4 organization chop.word #3 text.prefix$ }
            { title.field field.used =
                { format.btitle }
                { key.field field.used =
                    { key #3 text.prefix$ }
                    { "Internal error :001 on " cite$ * " label" * warning$ }
                  if$
                }
              if$
            }
          if$
        }
      if$
    }
  if$
}

FUNCTION {make.full.label}
{ author.field field.used =
    { author format.lab.names.full }
    { editor.field field.used =
        { editor format.lab.names.full }
        { organization.field field.used =
            { "The " #4 organization chop.word #3 text.prefix$ }
            { title.field field.used =
                { format.btitle }
                { key.field field.used =
                    { key #3 text.prefix$ }
                    { "Internal error :001 on " cite$ * " label" * warning$ }
                  if$
                }
              if$
            }
          if$
        }
      if$
    }
  if$
}

FUNCTION {make.abbr.label} %%%XXX change
{
  etal.allowed
    { author.field field.used =
        { author format.lab.names.abbr }
        { editor.field field.used =
            { editor format.lab.names.abbr }
            { organization.field field.used =
                { "The " #4 organization chop.word #3 text.prefix$ }
                { title.field field.used =
                    { format.btitle }
                    { key.field field.used =
                        { key #3 text.prefix$ }
                        {"Internal error :001 on " cite$ * " label" * warning$ }
                      if$
                    }
                  if$
                }
              if$
            }
          if$
        }
      if$
    }
    { make.full.label }
  if$
}

FUNCTION {output.bibitem}
{ newline$
  "\harvarditem{" write$
  make.abbr.label write$
  "}{" write$
  list.year write$
  "}{" write$
  cite$ write$
  "}" write$
  newline$
  ""
  before.all 'output.state :=
}

FUNCTION {list.label.output}
{ make.list.label " " * write$
}

FUNCTION {article}
{ output.bibitem
  list.label.output
  " " list.year * output.nonnull
  author "author" item.check
  crossref missing$
    { journal emphasize "journal" duplicate$ item.check
      " " * format.vol.num.pages * output
    }
    { format.article.crossref output.nonnull
      format.pages output
    }
  if$
  format.eprint output
  new.block
  note output
  fin.entry
  write.url
}

FUNCTION {book}
{ output.bibitem
  list.label.output
  " " list.year * output.nonnull
  author empty$
    { editor "author and editor" item.check }
    { crossref missing$
        { "author and editor" editor either.or.check }
        'skip$
      if$
    }
  if$
  title.field field.used =
    { skip$ }
    { format.btitle "title" output.check }
  if$
  crossref missing$
    { format.bvolume output
      format.number.series output
      format.edition output
      publisher "publisher" output.check
      address output
    }
    { format.book.crossref output.nonnull
      format.edition output
    }
  if$
  format.ISBN output
  new.block
  note output
  fin.entry
  write.url
}

FUNCTION {booklet}
{ output.bibitem
  list.label.output
  " " list.year * output.nonnull
  title.field field.used =
    { skip$ }
    { format.title quote "title" output.check }
  if$
  howpublished output
  address output
  new.block
  note output
  fin.entry
  write.url
}

FUNCTION {inbook}
{ output.bibitem
  list.label.output
  " " list.year * output.nonnull
  author empty$
    { editor "author and editor" item.check }
    { crossref missing$
        { "author and editor" editor either.or.check }
        'skip$
      if$
    }
  if$
  crossref missing$
    { format.bvolume output
      format.number.series output
      format.edition output
      publisher "publisher" output.check
      address output
    }
    { format.book.crossref output.nonnull
      format.edition output
    }
  if$
  format.chapter.pages "chapter and pages" output.check
  format.ISBN output
  new.block
  note output
  fin.entry
  write.url
}

FUNCTION {incollection}
{ output.bibitem
  list.label.output
  " " list.year * output.nonnull
  author "author" item.check
  crossref missing$
    { format.in.ed.booktitle "booktitle" output.check
      format.edition output
      format.bvolume output
      format.number.series output
      publisher "publisher" output.check
      address output
    }
    { format.incoll.inproc.crossref output.nonnull
    }
  if$
  format.chapter.pages output
  new.block
  note output
  fin.entry
  write.url
}

FUNCTION {inproceedings}
{ output.bibitem
  list.label.output
  " " list.year * output.nonnull
  author "author" item.check
  crossref missing$
    { format.in.ed.booktitle "booktitle" output.check
      format.bvolume output
      format.number.series output
      address empty$
        { organization output
          publisher output
        }
        { organization output
          publisher output
          address output.nonnull
        }
      if$
    }
    { format.incoll.inproc.crossref output.nonnull
    }
  if$
  format.pages output
  format.eprint output
  new.block
  note output
  fin.entry
  write.url
}

FUNCTION {conference} { inproceedings }

FUNCTION {manual}
{ output.bibitem
  list.label.output
  " " list.year * output.nonnull
  title.field field.used =
    { skip$ }
    { format.btitle "title" output.check }
  if$
  format.edition output
  author empty$
    { organization empty$
        { address output }
        'skip$
      if$
    }
    { organization output
      address output
    }
  if$
  format.eprint output
  new.block
  note output
  fin.entry
  write.url
}

FUNCTION {mastersthesis}
{ output.bibitem
  list.label.output
  " " list.year * output.nonnull
  author "author" item.check
  title.field field.used =
    { skip$ }
    { format.title "title" output.check }
  if$
  "Master's thesis" format.thesis.type output.nonnull
  school "school" output.check
  address output
  new.block
  note output
  fin.entry
  write.url
}

FUNCTION {misc}
{ output.bibitem
  list.label.output
  " " list.year * output.nonnull
  title.field field.used =
    { skip$ }
    { format.title quote output }
  if$
  howpublished output
  format.eprint output
  new.block
  note output
  fin.entry
  write.url
  empty.misc.check
}

FUNCTION {phdthesis}
{ output.bibitem
  list.label.output
  " " list.year * output.nonnull
  author "author" item.check
  title.field field.used =
    { skip$ }
    { title "title" output.check }
  if$
  "PhD thesis" format.thesis.type output.nonnull
  school "school" output.check
  address output
  format.eprint output
  new.block
  note output
  fin.entry
  write.url
}

FUNCTION {proceedings}
{ output.bibitem
  list.label.output
  " " list.year * output.nonnull
  format.bvolume output
  format.number.series output
  address empty$
    { editor empty$
        { skip$ }
        { organization output
        }
      if$
      publisher output
    }
    { editor empty$
        'skip$
        { organization output }
      if$
      publisher output
      address output.nonnull
    }
  if$
  format.eprint output
  new.block
  note output
  fin.entry
  %write.url
}

FUNCTION {techreport}
{ output.bibitem
  list.label.output
  " " list.year * output.nonnull
  author "author" item.check
  title.field field.used =
    { skip$ }
    { format.title "title" output.check }
  if$
  format.tr.number output.nonnull
  institution "institution" output.check
  address output
  format.eprint output
  new.block
  note output
  fin.entry
  write.url
}

FUNCTION {unpublished}
{ output.bibitem
  list.label.output
  " " list.year * output.nonnull
  author "author" item.check
  title.field field.used =
    { skip$ }
    { format.title "title" output.check }
  if$
  new.block
  note "note" output.check
  fin.entry
  write.url
}

FUNCTION {default.type} { misc }

MACRO {jan} {"January"}

MACRO {feb} {"February"}

MACRO {mar} {"March"}

MACRO {apr} {"April"}

MACRO {may} {"May"}

MACRO {jun} {"June"}

MACRO {jul} {"July"}

MACRO {aug} {"August"}

MACRO {sep} {"September"}

MACRO {oct} {"October"}

MACRO {nov} {"November"}

MACRO {dec} {"December"}

MACRO {acmcs} {"ACM Computing Surveys"}

MACRO {acta} {"Acta Informatica"}

MACRO {cacm} {"Communications of the ACM"}

MACRO {ibmjrd} {"IBM Journal of Research and Development"}

MACRO {ibmsj} {"IBM Systems Journal"}

MACRO {ieeese} {"IEEE Transactions on Software Engineering"}

MACRO {ieeetc} {"IEEE Transactions on Computers"}

MACRO {ieeetcad}
 {"IEEE Transactions on Computer-Aided Design of Integrated Circuits"}

MACRO {ipl} {"Information Processing Letters"}

MACRO {jacm} {"Journal of the ACM"}

MACRO {jcss} {"Journal of Computer and System Sciences"}

MACRO {scp} {"Science of Computer Programming"}

MACRO {sicomp} {"SIAM Journal on Computing"}

MACRO {tocs} {"ACM Transactions on Computer Systems"}

MACRO {tods} {"ACM Transactions on Database Systems"}

MACRO {tog} {"ACM Transactions on Graphics"}

MACRO {toms} {"ACM Transactions on Mathematical Software"}

MACRO {toois} {"ACM Transactions on Office Information Systems"}

MACRO {toplas} {"ACM Transactions on Programming Languages and Systems"}

MACRO {tcs} {"Theoretical Computer Science"}

READ

EXECUTE {init.field.constants}

FUNCTION {sortify}
{ purify$
  "l" change.case$
}

FUNCTION {sortify.names}
{ " \harvardand\ " " " replace.substring
  " et~al." " zzz" replace.substring
  sortify
}

FUNCTION {author.key.label}
{ author empty$
    { key empty$
        { title.field 'field.used := }
        { key.field 'field.used := }
      if$
    }
    { author.field 'field.used := }
  if$
}

FUNCTION {author.editor.key.label}
{ author empty$
    { editor empty$
        { key empty$
            { title.field 'field.used := }
            { key.field 'field.used := }
          if$
        }
        { editor.field 'field.used := }
      if$
    }
    { author.field 'field.used := }
  if$
}

FUNCTION {author.key.organization.label}
{ author empty$
    { key empty$
        { organization empty$
            { title.field 'field.used := }
            { organization.field 'field.used := }
          if$
        }
        { key.field 'field.used := }
      if$
    }
    { author.field 'field.used := }
  if$
}

FUNCTION {editor.key.organization.label}
{ editor empty$
    { key empty$
        { organization empty$
            { title.field 'field.used := }
            { organization.field 'field.used := }
          if$
        }
        { key.field 'field.used := }
      if$
    }
    { editor.field 'field.used := }
  if$
}

FUNCTION {sort.format.title}
{ 't :=
  "A " #2
    "An " #3
      "The " #4 t chop.word
    chop.word
  chop.word
  sortify
  #1 global.max$ substring$
}

FUNCTION {calc.label} %%%XXX change
{ make.abbr.label
  title.field field.used =
    { sort.format.title }
    { sortify.names }
  if$
  year field.or.null purify$ #-1 #4 substring$ sortify
  *
  'sort.label :=
}

FUNCTION {preliminaries} %%%XXX change
{ type$ "book" =
  type$ "inbook" =
  or
    'author.editor.key.label
    { type$ "proceedings" =
        'editor.key.organization.label
        { type$ "manual" =
            'author.key.organization.label
            'author.key.label
          if$
        }
      if$
    }
  if$
  author.field field.used = %%%XXX change
    {
      author num.names$ #2 >
        { #1 }
        { #0 }
      if$
      'etal.required :=
    }
    {
      editor.field field.used =
        {
          editor num.names$ #2 >
            { #1 }
            { #0 }
          if$
        }
        { #0 }
      if$
      'etal.required :=
    }
  if$
  #1 'etal.allowed :=
}

FUNCTION {first.presort}
{ calc.label
  sort.label
  title.field field.used =
    { skip$ }
    { "    "
      *
      make.list.label sortify.names
      *
      "    "
      *
      title field.or.null
      sort.format.title
      *
    }
  if$
  #1 entry.max$ substring$
  'sort.key$ :=
}

ITERATE {preliminaries}

ITERATE {first.presort}

SORT

STRINGS { last.sort.label next.extra last.full.label}

INTEGERS { last.extra.num last.etal.allowed}

FUNCTION {initialize.confusion}
{ #0 int.to.chr$ 'last.sort.label :=
  #0 int.to.chr$ 'last.full.label :=
  #1 'last.etal.allowed :=
}

FUNCTION {confusion.pass}
{ last.sort.label sort.label =
    { last.etal.allowed
        { last.full.label make.full.label sortify.names =
            { skip$ }
            { #0 'etal.allowed :=
              #0 'last.etal.allowed :=
            }
          if$
        }
        { #0 'etal.allowed := }
      if$
    }
    { sort.label 'last.sort.label :=
      make.full.label sortify.names 'last.full.label :=
      #1 'last.etal.allowed :=
    }
  if$
}

EXECUTE {initialize.confusion}

ITERATE {confusion.pass}

EXECUTE {initialize.confusion}

REVERSE {confusion.pass}

FUNCTION {initialize.last.extra.num}
{ #0 int.to.chr$ 'last.sort.label :=
  "" 'next.extra :=
  #0 'last.extra.num :=
}

FUNCTION {forward.pass}
{ last.sort.label sort.label =
    { last.extra.num #1 + 'last.extra.num :=
      last.extra.num int.to.chr$ 'extra.label :=
    }
    { "a" chr.to.int$ 'last.extra.num :=
      "" 'extra.label :=
      sort.label 'last.sort.label :=
    }
  if$
}

FUNCTION {reverse.pass}
{ next.extra "b" =
    { "a" 'extra.label := }
    'skip$
  if$
  year empty$
    { "n.d." extra.label emphasize * 'list.year := }
    { year extra.label emphasize * 'list.year := }
  if$
  extra.label 'next.extra :=
}

ITERATE {first.presort}

SORT

EXECUTE {initialize.last.extra.num}

ITERATE {forward.pass}

REVERSE {reverse.pass}

FUNCTION {second.presort}
{ make.list.label
  title.field field.used =
    { sort.format.title }
    { sortify.names }
  if$
  "    "
  *
  list.year field.or.null sortify
  *
  "    "
  *
  title.field field.used =
    { skip$ }
    { title field.or.null
      sort.format.title
      *
    }
  if$
  #1 entry.max$ substring$
  'sort.key$ :=
}

ITERATE {second.presort}

%SORT

FUNCTION {begin.bib}
{ preamble$ empty$
    'skip$
    { "\harvardpreambledefs{%" write$ newline$
      preamble$ write$ "}" write$ newline$
      "\harvardpreambletext{%" write$ newline$
      preamble$ write$ "}" write$ newline$ }
  if$
  "\begin{thebibliography}{xx}" write$ newline$
}

EXECUTE {begin.bib}

EXECUTE {init.state.consts}

ITERATE {call.type$}

FUNCTION {end.bib}
{ newline$
  "\end{thebibliography}" write$ newline$
}

EXECUTE {end.bib}