\documentclass{article}

\newcommand{\booktitle}[1]{\textit{#1}}
\def\mdash{\textemdash}
\def\amslatex{{\protect\AmS-\protect\LaTeX}}

\begin{document}

This is a test1~\cite{aaaaa}
This is a test2~\cite{bbbbb}

\begin{thebibliography}{9}

\bibitem{aaaaa}Amer. Math. Soc., Providence, RI,
    1994; distributed with the AMSFonts package.

\bibitem{bbbbb}Amer. Math. Soc., Providence, RI,
    1995; distributed with the AMSFonts package.

\end{thebibliography}

\end{document}

