'Undefined control sequence \byear'

Question

I'm trying to build this bibliography according to the specifications of the Institute of Mathematical Statistics. As such, I've been using the thebibliography environment. My code looks like this:

\begin{thebibliography}{4}
% BibTex style file: imsart-number.bst, 2013-01-28
% Default style options (sort=1,type=number).
% Used options (sort=1,type=number).

\bibitem{finger1961}
\begin{barticle}[author]
\bauthor{\bsnm{Finger},~\bfnm{Harold~B.}\binits{H.~B.}}
(\byear{1961}).
\btitle{Nuclear rockets and the space challenge}.
\bjournal{Astronautics}
\bvolume{6}
\bpages{24}.
\end{barticle}
\endbibitem

\bibitem{moss2001moving}
\begin{bbook}[author]
\bauthor{\bsnm{Moss},~\bfnm{George}\binits{G.}} \AND
  \bauthor{\bsnm{Thomas},~\bfnm{Evan~A}\binits{E.~A.}}
(\byear{2001}).
\btitle{Moving on: The American people since 1945}.
\bpublisher{Prentice Hall}.
\end{bbook}
\endbibitem

\bibitem{nasalaw}
\begin{barticle}[author]
\bauthor{\bsnm{Rayburn},~\bfnm{Sam}\binits{S.}} \AND
  \bauthor{\bsnm{Nixon},~\bfnm{Richard}\binits{R.}}
(\byear{1958}).
\btitle{National Aeronautics and Space Act}.
\bjournal{U.S. Code}
\bvolume{85-567}
\bpages{426..438}.
\end{barticle}
\endbibitem

\bibitem{history2013}
\begin{b}[author]
(\byear{2013}).
\btitle{Space Race: Cold War Front}.
\end{b}
\endbibitem
\end{thebibliography}

The trouble is, I keep getting this error:

    (/usr/local/texlive/2013/texmf-dist/tex/generic/oberdiek/se-ascii-print.def)
    ./Space_race_bibliography.tex:112: Undefined control sequence.
    l.112 (\byear
             {2013}).
    ?

Is there some package I forgot to require? All I have in the preamble is \usepackage{imsart}.

EDIT: Here is a MWE:

\documentclass{imsart}

\usepackage{amsthm,amsmath}
\usepackage[colorlinks,citecolor=blue,urlcolor=blue]{hyperref}

% provide arXiv number if available:
%\arxiv{arXiv:0000.0000}

% put your definitions there:
\startlocaldefs
\endlocaldefs

\begin{document}

\begin{frontmatter}

% "Title of the Paper"
\title{Space Race Jackdaw Bibliography}
\runtitle{Space Race Jackdaw Bibliography}

% indicate corresponding author with \corref{}
% \author{\fnms{John} \snm{Smith}\thanksref{t2}\corref{}\ead[label=e1]{[email protected]}\ead[label=e2,url]{www.foo.com}}
% \thankstext{t2}{Thanks to somebody} 
% \address{line 1\\ line 2\\ \printead{e1}\\ \printead{e2}}

\begin{aug}
\author{\fnms{Benji} \snm{Miller}\ead[label=e1]{[email protected]}}
\and
\author{\fnms{Noah} \snm{Goldman}\ead[label=e2]{[email protected]}}
\address{Wildwood School\\
11811 Olympic Blvd.\\
Los Angeles, CA 90064 \\
\printead{e1,e2}}
\end{aug}
%\begin{abstract}
%\end{abstract}

%\begin{keyword}[class=MSC]
%\kwd[Primary ]{}
%\kwd{}
%\kwd[; secondary ]{}
%\end{keyword}

%\begin{keyword}
%\kwd{}
%\kwd{}
%\end{keyword}

% history:
% \received{\smonth{1} \syear{0000}}

%\tableofcontents

\end{frontmatter}

\nocite{*}

\bibliographystyle{imsart-number}
\begin{thebibliography}{4}
% BibTex style file: imsart-number.bst, 2013-01-28
% Default style options (sort=1,type=number).
% Used options (sort=1,type=number).

\bibitem{finger1961}
\begin{barticle}[author]
\bauthor{\bsnm{Finger},~\bfnm{Harold~B.}\binits{H.~B.}}
(\byear{1961}).
\btitle{Nuclear rockets and the space challenge}.
\bjournal{Astronautics}
\bvolume{6}
\bpages{24}.
\bptok{imsref}
\end{barticle}
\endbibitem

\bibitem{moss2001moving}
\begin{bbook}[author]
\bauthor{\bsnm{Moss},~\bfnm{George}\binits{G.}} \AND
  \bauthor{\bsnm{Thomas},~\bfnm{Evan~A}\binits{E.~A.}}
(\byear{2001}).
\btitle{Moving on: The American people since 1945}.
\bpublisher{Prentice Hall}.
\bptok{imsref}
\end{bbook}
\endbibitem

\bibitem{nasalaw}
\begin{barticle}[author]
\bauthor{\bsnm{Rayburn},~\bfnm{Sam}\binits{S.}} \AND
  \bauthor{\bsnm{Nixon},~\bfnm{Richard}\binits{R.}}
(\byear{1958}).
\btitle{National Aeronautics and Space Act}.
\bjournal{U.S. Code}
\bvolume{85-567}
\bpages{426..438}.
\bptok{imsref}
\end{barticle}
\endbibitem

\bibitem{history2013}
\begin{b}[author]
(\byear{2013}).
\btitle{Space Race: Cold War Front}.
\bptok{imsref}
\end{b}
\endbibitem

\end{thebibliography}


\end{document}

Answer 1

A short look into imsart-number.bst suggests, that only predefined records are allowed. I don't know the type of your last entry, hence I have chosen book, but the following changes show the general idea.

\documentclass{imsart}

\usepackage{amsthm,amsmath}
\usepackage[colorlinks,citecolor=blue,urlcolor=blue]{hyperref}

% provide arXiv number if available:
%\arxiv{arXiv:0000.0000}

% put your definitions there:
\startlocaldefs
\endlocaldefs

\begin{document}

\begin{frontmatter}

% "Title of the Paper"
\title{Space Race Jackdaw Bibliography}
\runtitle{Space Race Jackdaw Bibliography}

% indicate corresponding author with \corref{}
% \author{\fnms{John} \snm{Smith}\thanksref{t2}\corref{}\ead[label=e1]{[email protected]}\ead[label=e2,url]{www.foo.com}}
% \thankstext{t2}{Thanks to somebody} 
% \address{line 1\\ line 2\\ \printead{e1}\\ \printead{e2}}

\begin{aug}
\author{\fnms{Benji} \snm{Miller}\ead[label=e1]{[email protected]}}
\and
\author{\fnms{Noah} \snm{Goldman}\ead[label=e2]{[email protected]}}
\address{Wildwood School\\
11811 Olympic Blvd.\\
Los Angeles, CA 90064 \\
\printead{e1,e2}}
\end{aug}
%\begin{abstract}
%\end{abstract}

%\begin{keyword}[class=MSC]
%\kwd[Primary ]{}
%\kwd{}
%\kwd[; secondary ]{}
%\end{keyword}

%\begin{keyword}
%\kwd{}
%\kwd{}
%\end{keyword}

% history:
% \received{\smonth{1} \syear{0000}}

%\tableofcontents

\end{frontmatter}

\nocite{*}

\bibliographystyle{imsart-number}
\begin{thebibliography}{4}
% BibTex style file: imsart-number.bst, 2013-01-28
% Default style options (sort=1,type=number).
% Used options (sort=1,type=number).

\bibitem{finger1961}
\begin{barticle}[author]
\bauthor{\bsnm{Finger},~\bfnm{Harold~B.}\binits{H.~B.}}
(\byear{1961}).
\btitle{Nuclear rockets and the space challenge}.
\bjournal{Astronautics}
\bvolume{6}
\bpages{24}.
%\bptok{imsref}
\end{barticle}
\endbibitem

\bibitem{moss2001moving}
\begin{bbook}[author]
\bauthor{\bsnm{Moss},~\bfnm{George}\binits{G.}} \AND
  \bauthor{\bsnm{Thomas},~\bfnm{Evan~A}\binits{E.~A.}}
(\byear{2001}).
\btitle{Moving on: The American people since 1945}.
\bpublisher{Prentice Hall}.
%\bptok{imsref}
\end{bbook}
\endbibitem

\bibitem{nasalaw}
\begin{barticle}[author]
\bauthor{\bsnm{Rayburn},~\bfnm{Sam}\binits{S.}} \AND
  \bauthor{\bsnm{Nixon},~\bfnm{Richard}\binits{R.}}
(\byear{1958}).
\btitle{National Aeronautics and Space Act}.
\bjournal{U.S. Code}
\bvolume{85-567}
\bpages{426..438}.
%\bptok{imsref}
\end{barticle}
\endbibitem

\bibitem{history2013}
%\begin{b}[author]
\begin{bbook}
(\byear{2013}).
\btitle{Space Race: Cold War Front}.
%\bptok{imsref}
\end{bbook}
%\end{b}
\endbibitem

\end{thebibliography}


\end{document}