How to cite a paper as shortened first author name and year [Ste2002]?
There's an easier LaTeX solution (compared to another answer):

\documentclass{article}
\begin{document}
\section{First section}

First statement \cite{gascuel97}, and a second statement \cite{sokal58}.

\bibliographystyle{alpha}  %Sets [Ste2002] bibligraphy style
\bibliography{sample}      %Imports bibliography file

\end{document}