\begin{table}%t5
%\centering
\par
\caption{\label{tab:infraref}References for Table~\ref{tab:infrared}.}
\begin{tabular}{l l l l}
\hline\hline\noalign{\smallskip}
{Number} &    {Reference}   &   {Number}      &{Reference} \\
\hline
42      &    \citet{Sanchez2003}    &  52      &   \citet{Wright1998}       \\
43      &   \citet{Barkhouse2001}   &  53      &   \citet{Carballo1998}     \\
44      &   \citet{Snellen1996}     &  54      &   \citet{Sanders1988}      \\
45      &   \citet{Bloom1994}       &  55      &   \citet{Padovani2006}     \\
46      &   \citet{Gonzalez2001}    &  56      &   \citet{Puschell1982}     \\
47      &   \citet{Jarrett2003}     &  57      &   \citet{Villani1999}      \\
48      &   \citet{Skrutskie2003}   &  58      &   \citet{Xie1998}          \\
49      &   \citet{deVries1998}     &  59      &   \citet{Golombek1988}     \\
50      &   \citet{Lilly1985}       &  60      &   \citet{Knapp1990}        \\
51      &   \citet{Heckman1983}     &  61      &   \citet{Kotilainen2005}   \\
\hline
\end{tabular}
%\vspace*{-1.5mm}
\end{table}