# Removing comma if exactly two authors from *.bst file (natbib) in AIAA paper template

I'm using natbib with a custom .bst file for a conference paper. Unfortunately, the .bst file results in a comma separating the authors names when there are only two authors, and I need to remove this comma.

In the .bst file, here is the format.names function:

FUNCTION {format.names}
{ 'bibinfo :=
duplicate$empty$ 'skip${ 's := "" 't := #1 'nameptr := s num.names$ 'numnames :=
numnames 'namesleft :=
{ namesleft #0 > }
{ s nameptr
"{vv~}{ll}{, f.}{, jj}"
format.name$bibinfo bibinfo.check 't := nameptr #1 > { namesleft #1 > { ", " * t * } { s nameptr "{ll}" format.name$ duplicate$"others" = { 't := } { pop$ }
if$"," * t "others" = { " " * bbl.etal * } { bbl.and space.word * t * } if$
}
if$} 't if$
nameptr #1 + 'nameptr :=
namesleft #1 - 'namesleft :=
}
while$} if$
}


I'm not familiar enough with the scripting language used in the .bst file to modify it. I believe I need to add another condition for when the total number of names is 2, and to modify:

namesleft #1 >
{ ", " * t * }


As an aside, I believe this bst file was created by the conference organizer using the bst creation wizard.

Unfortunately, I cannot move forward with the editing process until this is fixed... Could anyone assist me?

Edit: Here is a MWE:

\documentclass[conf]{new-aiaa}

\begin{document}

Here is a MWE containing a sample citation and references list \cite{peyret2012computational}.

\bibliography{sample}

\end{document}


To get this MWE to work, you need the following sample.bib file

@inbook{peyret2012computational,
title={Computational Methods for Fluid Flow},
edition={2},
author={Peyret, Roger and Taylor, Thomas D},
year={1983},
publisher={Springer-Verlag},
chapter={7, 14}
}


and the new-aiaa.cls and new-aiaa.bst files, which can be sourced from the presenter resources page found at

https://www.aiaa.org/home/events-learning/events/Technical-Presenter-Resources

or directly from Overleaf at

Just a note, I have this issue with conference papers as well, but this is for my thesis which uses the new-aiaa.bst file for references, but of course, a different cls file.

Thank you for your patience and assistance.

• Can you post a link to the whole .bst file and add a sample document and .bib item showing the problem? – Alan Munn Jun 26 at 19:38
• @AlanMunn yes, thank you very much for your patience and your assistance. I will edit the main question with the requested information and MWE. – Matt Jun 27 at 1:36
• Is there anything I could add to this question? I could really use some help on this one :( – Matt Jun 30 at 3:25

The following does what you want:

Make a copy of new-aiaa.bst and rename it something sensible, like new-aiaa-nocomma.bst.

In the function format.names there is a line (line 454) that contains just the following:

"," *


Replace this line with the following lines:

numnames #2 =
{" " *}
{"," *}
if\$


Here's a MWE using article class. Since the new-aiaa.bst was created by the journal, I don't think you should change the style for submission to the journal. If you do, you will need to patch the new-aiaa.cls to use the modified .bst file, since the class loads the style itself.

\begin{filecontents}{\jobname.bib}
@inbook{peyret2012computational,
title={Computational Methods for Fluid Flow},
edition={2},
author={Peyret, Roger and Taylor, Thomas D},
year={1983},
publisher={Springer-Verlag},
chapter={7, 14}
}
@article{hughes1989new,
title={A new finite element formulation for computational fluid dynamics: {VIII}. The {Galerkin}/least-squares method for advective-diffusive equations},
author={Hughes, Thomas JR and Franca, Leopoldo P and Hulbert, Gregory M},
journal={Computer Methods in Applied Mechanics and Engineering},
volume={73},
number={2},
pages={173--189},
year={1989},
publisher={Elsevier}
}
\end{filecontents}
%\documentclass[conf]{new-aiaa} % Class will need to be changed to use the modified .bst
\documentclass{article}
\usepackage[sort&compress,numbers]{natbib}
\bibliographystyle{new-aiaa-nocomma}
\begin{document}
\cite{peyret2012computational,hughes1989new}
\bibliography{\jobname}
\end{document}


• Always my sincere compliments. Very elegant. – Sebastiano Jun 30 at 10:54
• Thank you so very very much! This did the trick! Very elegant solution! – Matt Jul 1 at 17:33