\begin{table}%T1
\caption{ Dielectronic recombination resonance
strengths ($10^{-20}$~cm$^2$~eV) for O$^{7+}$.
\label{tabo7}}
%\begin{center}
{
\begin{tabular}{rcccc}
\hline
\hline
$n$ & \quad HF$^a$ & TF$^a$ & STO$^b$ & Observed$^c$ \\
\hline
2 & 13.8 & 11.1 & 13.2 & 12.4 \\
3 & 23.6 & 21.7 & 21.5 & 24.5 \\
4 & 19.1 & 18.6 & 18.4 & 18.0 \\
5 & 16.3 & 15.4 & 15.3 & 14.3 \\
6 & 13.2 & 12.0 & 11.9 & \phantom{4}9.6 \\
$\ge$7&  & 45.1 & 46.3 & 43.6 \\
\hline 
\end{tabular}}
\parbox{6cm}{
$^a$ Pindzola \etal (\cite{pin90b}).\\
$^b$ Present work.\\
$^c$ Kilgus \etal (\cite{kil90}).}
%\end{center}
\end{table}