Natbib: merging author(s) with the same name(s)

Question

I defined the following command in my manuscript:

\newcommand{\citesep}[2]{\citeauthor{#1}#2~\cite{#1}}

which allows me to print, for instance, "Knuth and Tarjan's algorithm [16]" using \citesep{knuth-681}{'s algorithm}.

However, this causes an unwanted behaviour with papers with the same authors; for example, \citesep{knuth-681,knuth-702}{'s work} produces "Knuth and Tarjan, Knuth and Tarjan's work [16,17]" whereas I'd like it to print "Knuth and Tarjan's work [16,17]".

Any idea how to fix that?

Answer 1

I finally came up with what seems like a solution. I did the following:

• Dig into natbib.sty in search for the macro segment that is responsible for typesetting the author's name(s). Trial and error revealed that \NAT@nm does the "raw" typesetting and in turn is formatted by \NAT@nmfmt.

• Redefine \NAT@nmfmt so that it will additionally typeset the expansion of the new \nameadjunct command (which does nothing by default).

• Define the new commands \citeposs and \citesep which are wrappers for \citet but will locally redefine \nameadjunct to "'s" respectively \citesep's second mandatory argument.

---

\documentclass{article}

\usepackage{natbib}

\newcommand*{\nameadjunct}{\relax}
\makeatletter
\renewcommand*{\NAT@nmfmt}[1]{\NAT@up #1\nameadjunct}
\makeatother

\newcommand*{\citeposs}[2][]{%
  \begingroup
  \renewcommand*{\nameadjunct}{'s}%
  \citet[#1]{#2}%
  \endgroup
}

\newcommand*{\citesep}[3][]{%
  \begingroup
  \renewcommand*{\nameadjunct}{#3}%
  \citet[#1]{#2}%
  \endgroup
}

\begin{filecontents}{\jobname.bib}
@misc{Knu01,
  author = {Knuth, Donald E. and Tarjan, Robert E.},
  year = {2001},
  title = {A new algorithm},
}
@misc{Knu02,
  author = {Knuth, Donald E. and Tarjan, Robert E.},
  year = {2002},
  title = {More about our algorithm},
}\end{filecontents}

\begin{document}

\citet{Knu01,Knu02}

\citeposs{Knu01,Knu02}

\citesep{Knu01,Knu02}{'s algorithm}

\bibliographystyle{plainnat}
\bibliography{\jobname}

\end{document}

Answer 2

I don't comprehend natbib's intricacies, but here's a solution using biblatex. (Note: My \citesep command works well for simultaneously citing several papers with the same author(s), but will yield strange results for different authors.)

\documentclass{article}

\usepackage{biblatex}

\makeatletter

% COPIED FROM \newbibmacro*{textcite}
\newbibmacro*{textadjunctcite}{%
  \iffieldequals{namehash}{\cbx@lasthash}
    {\multicitedelim}
    {\cbx@tempa
     \ifnameundef{labelname}
       {\printfield[citetitle]{labeltitle}}
%       {\printnames{labelname}}% DELETED
       {\printnames{labelname}% NEW
       \printfield{adjunct}}% NEW
     \addspace\bibopenbracket}%
  \ifnumequal{\value{citecount}}{1}
    {\usebibmacro{prenote}}
    {}%
  \usebibmacro{cite}%
  \savefield{namehash}{\cbx@lasthash}%
  \gdef\cbx@tempa{\bibclosebracket\multicitedelim}}

% COPIED FROM \DeclareCiteCommand{\textcite}
\DeclareCiteCommand{\textadjunctcite}
  {\let\cbx@tempa=\empty
   \undef\cbx@lasthash}
  {\usebibmacro{citeindex}%
%   \usebibmacro{textcite}}% DELETED
   \usebibmacro{textadjunctcite}}% NEW
  {}
  {\usebibmacro{postnote}%
   \bibclosebracket}

\newcommand*{\citeposs}[2][]{%
  \def\abx@field@adjunct{'s}%
  \textadjunctcite[#1]{#2}%
}

\newcommand*{\citesep}[3][]{%
  \def\abx@field@adjunct{#3}%
  \textadjunctcite[#1]{#2}%
}

\makeatother

\usepackage{filecontents}

\begin{filecontents}{\jobname.bib}
@misc{Knu01,
  author = {Knuth, Donald E. and Tarjan, Robert E.},
  year = {2001},
  title = {A new algorithm},
}

@misc{Knu02,
  author = {Knuth, Donald E. and Tarjan, Robert E.},
  year = {2002},
  title = {More about our algorithm},
}
\end{filecontents}

\bibliography{\jobname}

\begin{document}

This was \citeposs{Knu01,Knu02} work~\dots

As shown in \citesep{Knu01,Knu02}{'s algorithm}~\dots

\printbibliography

\end{document}

EDIT: Extended MWE to include a \citeposs command.