\begin{table}%t3
\caption{\label{tab3}NGC~6741: chemical abundances (relative to log~$H$ = 12).}
%\centering
\par
\begin{tabular}{lcccccccc}
\hline\hline
Reference& He& C& N& O &Ne&S&Cl&Ar\\
\hline
Hyung \& Aller (\cite{Hyung1997}) (icf)&11.01&8.86&8.38&8.73&8.12&6.89&5.43&6.49\\
Hyung \& Aller (\cite{Hyung1997}) (model B)&11.04&8.90&8.15&8.65&8.00&6.76&5.34&6.54\\
Pottasch et~al. (\cite{Pottasch2001})&11.04&8.81&8.45&8.82&8.26&7.04&--&6.69\\
Pottasch et~al. (\cite{Pottasch2002})&11.04&8.56&8.26&8.65&8.18&6.90&5.26&6.51\\
Perinotto et~al. (\cite{Perinotto2004b})&11.08&-- &8.31&8.70&8.16&6.70&-- &6.54\\
This paper (icf) &11.04&--&8.20&8.66&8.08&6.78&-- &6.54\\
This paper (CLOUDY) &11.04&--&8.28&8.66&8.08&6.90&-- &6.54\\
\hline
\end{tabular}
\end{table}