\begin{table}%t3
%\centering
\par
  \caption{References for the data taken from the literature.}
  \label{references}
\par
\begin{tabular}{ll}
  \hline
  \hline
  \noalign{\smallskip}
Reference & Reference \\
\par
  \noalign{\smallskip}
  \hline
  \noalign{\smallskip}
\par
Beasley  et~al. (\cite{beasley})        & Owen  et~al. (\cite{owen}) \\
Becker  et~al. (\cite{becker})          & Pauliny-Toth  et~al. (\cite{pt78}) \\
Bondi  et~al. (\cite{bondi})            & Peng et~al. (\cite{peng}) \\
Dagkesamanskii  et~al. (\cite{dagkesa}) & Perley  (\cite{perley82}) \\
Dallacasa et~al. (\cite{dalla00})       & Reich  et~al. (\cite{reich98})\\
Douglas  et~al. (\cite{douglas96})      & Reich  et~al. (\cite{reich00}) \\
Drinkwater  et~al. (\cite{drink})       & Reuter  et~al. (\cite{reuter})\\
Edelson  et~al. (\cite{edelson})        & Robson  et~al. (\cite{robson}) \\
Gear et~al. (\cite{gear})               & Seielstad et~al. (\cite{seielstad}) \\
Geldzahler \& Witzel (\cite{gw})          & Steppe  et~al. (\cite{steppe})\\
Ghosh  et~al. (\cite{ghosh})            & Ter\"asranta  et~al. (\cite{terasranta87}) \\
Gregory \& Condon (\cite{gc})             & Ter\"asranta  et~al. (\cite{terasranta92})\\ 
Gregory et~al. (\cite{gregory})           & Ter\"asranta  et~al. (\cite{terasranta98}) \\
Griffith et~al. (\cite{griffith})         & Tornikoski  et~al. (\cite{merja93}) \\
Kovalev  et~al. (\cite{kovalev99})      & Ulvestad  et~al. (\cite{ulve81})\\
K\"uhr et~al. (\cite{kuhr})             & Visser  et~al. (\cite{visser95}) \\
Large  et~al. (\cite{large91})          & Wiren et~al. (\cite{wiren})\\
Lawrence  et~al. (\cite{lawrence})      &  Wright  et~al. (\cite{wright91})\\
O'Dea  et~al. (\cite{odea90})           & Wright  et~al. (\cite{wright96}) \\
%&\\
\multicolumn{2}{l}{Verkhodanov et~al. (\cite{cats}, and the references therein)  } \\
 \hline
\end{tabular}
 \end{table}