# References: Undefined control sequence

I am using a bibliographystyle file, bibliography file with my .tex file and I get the following error but do not understand if I have an issue with the style file or my references file .bib or the way I am citing them. I do get the references listed in the pdf without a "comma" between name and year.

! Undefined control sequence.
\b@armycorps ->\citeauthoryear
{arm}{2012}


Here is the code and the relevant files to download bibstyle and bib. Here is MWE:

\documentclass[11pt,a4paper]{article}
\usepackage[margin=1.5in]{geometry}
\usepackage{setspace}
\usepackage{url}
\usepackage{verbatim}
\usepackage{booktabs}

\setstretch{1.5}
\begin{document}
\section{Introduction}
n the US Army Corps of Engineers National Inventory of Dams
\cite{armycorps}, over 50 years old expected to rise to 85\%
\cite{mitdams},

\bibliographystyle{named}
\bibliography{ijcai17}
\end{document}


Entry for armycorps:

@misc{armycorps,
title = "National inventory of dams",
howpublished = "\url{http://nid.usace.army.mil/cm_apex/f?p=838:4:0::NO}",
year = "2012",
note = "[Online; accessed 15-November-2016]"
}

• What is your entry for armycorps in ijcai17.bib? – Teepeemm Dec 4 '16 at 3:14
• Sorry about that. Thanks for adding it here. – tacqy2 Dec 4 '16 at 4:05
• The code you've posted is not the source of the error. The error is caused by the use of \citeauthoryear which is undefined. – cfr Dec 4 '16 at 4:38
• @CarLaTeX That's true, my bad! – tacqy2 Dec 4 '16 at 5:58

If you use the named bibliography style, you must also use the named package: \usepackage{named}. Here the \citeauthoryear command is defined. Strangely enough, this is not installed on my TeXlive 2016 system, while the bibliography style is installed. This is inconsistent. So either you have to install named.sty separately, or use another bibliography style.