\begin{table}%t2
%\begin{center}
\par
\caption{List of the sources with spin frequencies and peak
separations.}
 \label{tab2}
 \begin{tabular}{lccc}
\hline \hline\\[-3mm]
 Sources$^{*}$ & $\lan\dn\ran(\sigma)^{1}$ &
$\lan\dn\ran/\nu_{\rm s}^{2}$ & $\nu_{\rm 2~min}/\nu_{\rm s}^{3}$\\
 & (Hz) & &\\
\hline {\bf Millisecond pulsar}\\
\hline
XTE J1807-294      & 215(5.9)       &  1.13 & 1.8 \\
SAX J1808.4-3658   & 195(4.0)$^{a}$ &  0.49 & 1.7 \\
\hline {\bf Atoll source}\\
\hline
4U 1608-52         &  287(7.2)     &  0.46 & 1.3 \\
4U 1636-53         &  286(9.6)     &  0.49 & 1.7 \\
4U 1702-43         &  333(8.7)     &  1.01 & 3.2 \\
4U 1728-34         &  327(5.8)     &  0.90 & 1.6 \\
KS 1731-260        &  266(8.7)     &  0.51 & 2.2 \\
4U 1915-05         &  338(12.1)    &  1.25 & 1.9 \\
\hline 
%\hline
\end{tabular}
%%\end{center}
\par
%\vskip 0.3cm
%\begin{minipage}{\linewidth}
\parbox{9cm}{
%\begin{tabular}{p{\linewidth}}
{ $^{*}$  Data are taken from the references listed in Table~\ref{tab1};  
$^{1}$  averaged peak separation and its standard deviation;
$^{2}$  ratio of averaged peak separation to spin frequency;
$^{3}$  ratio of the minimum upper-frequency to
 spin frequency; $^{a}$  measured  error
of the single pair of twin kHz QPOs. }}
%\end{tabular}
%\end{minipage}
%\end{center}
\par
\end{table}