To produce a two-column list of references when all citations are entered
explicitly within the body of the text, one can (ab)use the tabular
environment as in the following example:
\setlength{\tabcolsep}{0pt}
\begin{tabular}{p{3.25in}p{3.25in}}
\multicolumn{2}{c}{\bf References} \\
{A. Nonymous et al.\ 2005, \aap 123, 456} &
{M.Y. Student 2003, \aj 123, 4567} \\
{A.N. Other \& S.O.M. Ebody 2004, \pasp 123, 456} &
{W.O. Zhe et al.\ 2000, \mnras 345, 678} \\
\end{tabular}
This uses the fact that the entries in columns with a format specification
of p{width} are typeset as if they were contained within a
\parbox.
| References | |
| A. Nonymous et al. 2005, A&A 123, 456 | M.Y. Student 2003, AJ 123, 4567 |
| A.N. Other & S.O.M. Ebody 2004, PASP 123, 456 | W.O. Zhe et al. 2000, MNRAS 345, 678 |