\begin{table}%t1
\caption{\label{tab:radioBCD}Radio sample.}
%\centerline
 {\small 
\begin{tabular}{@{}lcccccc@{}}
\hline\hline \noalign{\smallskip}
Name & $d$ & $n_{\rm e}$ & $D$ &
$12+\log{\rm (O/H)}$ & Ref.$^{\rm a,~ b}$ \\
& (Mpc) & (cm$^{-3}$) & (pc) &\\
\hline
He~2$-$10 & 10.4 & 10~000 & 6.4 & 8.06 & 1, 9 \\
&      & 3300  & 6.4 &      & 1 \\
I~Zw~18 & 14.6 & 4 & 626 & 7.17 & 3, 10 \\
II~Zw~40 & 11.1 & 35~000 & 1.1 & 8.13 & 3, 10 \\
M~33     & 0.84$^{\rm c}$ & 3700  & 3.7 & 8.78 & 5, 17 \\
Mrk~8    & 52.5 & 20~000 & 3.7 & 8.51 & 4, 13 \\
Mrk~33   & 25.5 & 9000  & 1.9 & 8.40 & 4, 14 \\
Mrk~1089 & 54.6 & 20~000 & 3.9 & 8.04 & 4, 12 \\
Mrk~1236 & 29.6 & 20~000 & 0.5 & 8.07 & 4, 16 \\
NGC~4214n & 3.8 & 70~000 & 0.4 & 8.22 & 4, 11 \\
NGC~5253 & 2.5 & 7500 & 2.7 & 8.17 & 1, 8 \\
         &     & 40~000 & 0.9 &   & 2 \\
NGC~6946 & 5.6  & 3700  & 9.9 & 9.12 & 5, 15 \\
NGC~253  & 3.4  & 10~000 & 3.3   & 8.88 & 5, 17 \\
Pox~4    & 52.5 & 7000 & 2.6 & 7.95 & 4, 14 \\
SBS~0335$-$052   & 53.7    & 1500 & 22.7 & 7.30 & 6, 10\\
SBS~0335$-$052$-$1   & 53.7    & 4300 & 9.6 & 7.30 & 7, 10\\
SBS~0335$-$052$-$2   & 53.7    & 7900 & 5.4  & 7.30 & 7, 10\\
Tol~35   & 25.2 & 20~000 & 0.5 & 8.11 & 4, 15 \\
VII~Zw~19 & 67.4 & 5000 & 4.8 & 8.71 & 4, 14 \\
\hline
\end{tabular}}
\medskip
 $^{{\rm a}}$  References for the radio interferometric observations:
1)~Mohan et~al.  (\cite{mohan01}); 2)~Turner et~al. (\cite{turner00});
3)~Beck et~al.  (\cite{beck02}); 4)~Beck et~al. (\cite{beck00});
5)~Johnson et~al.  (\cite{johnson01}); 6)~Hunt et~al. (\cite{hunt04});
7)~Johnson et~al. (\cite{johnson09}); $^{\rm b}$~references for the oxygen abundance: 8)~Walsh \& Roy (\cite{walsh89}); 9)~Vacca \& Conti (\cite{vacca92}); 10)~Thuan \& Izotov (\cite{thuan05}); 11)~Kobulnicky \& Skillman (\cite{kobulnicky96}); 12)~Guseva et~al. (\cite{guseva00});
13)~Shi et~al. (\cite{shi05}); 14)~Kunth \& Joubert (\cite{kunth85});
15)~Kobulnicky et~al. (\cite{kobulnicky99b}); 16)~Buckalew et~al. (\cite{buckalew05}); 17)~Garnett (\cite{garnett02}); $^{{\rm c}}$~the distance of M~33 is taken from Freedman et~al. (\cite{freedman91}).
%\vspace*{2.5mm}
\end{table}