\begin{table}%t1
\caption{\label{Photoabsorption}References for photoabsorption cross sections.}
\small%\centering
\par
\begin{tabular}[h]{cc}
\hline					\hline
Species	& References 					\\
\hline
H		& \citet{Samson66}	\\
H$_{2}$	& \citet{Chung93} 	\\
He		& \citet{Yan98}		\\
CH$_{4}$& \citet{Samson89} and \citet{Au93}	\\
\hline
\end{tabular}
\end{table}