\begin{table}%T6
%\centering
\par
\caption{References for the [O/Fe] and [Na/Fe] ratios from high resolution
analyses in globular clusters used to derive the overall Na-O anticorrelation
shape.}
 {
\begin{tabular}{lll}
\hline\hline
Cluster  &  stars &  Reference\\
\hline
NGC~104 (47 Tuc)  &  SGB+TO &  Carretta et~al. (\cite{Carretta04b})    \\
                  &  RGB    &  Norris \& Da Costa (\cite{Norris95}) \\ 
                  &  RGB    &  Carretta (\cite{Carretta94})           \\ 
NGC~288           &  RGB    &  Shetrone \& Keane (\cite{Shetrone00})  \\ 
NGC~362           &  RGB    &  Shetrone \& Keane (\cite{Shetrone00})  \\ 
NGC~2808          &  RGB    &  Carretta et~al. (\cite{Carretta04a})    \\ 
                  &  RGB    &  present study             \\ 
NGC~3201          &  RGB    &  Gonzalez \& Wallerstein (\cite{Gonzalez98}) \\ 
NGC~5272 (M~3)    &  RGB    &  Cohen \& Melendez (\cite{Cohen05})  \\ 
                  &  RGB    &  Sneden et~al. (\cite{Sneden04})      \\ 
NGC~5904 (M~5)    &  RGB    &  Ivans et~al. (\cite{Ivans01})       \\ 
NGC~6121 (M~4)    &  RGB    &  Ivans et~al. (\cite{Ivans99})       \\ 
NGC~6205 (M~13)   &RGB+SGB+TO&  Cohen \& Melendez (\cite{Cohen05})  \\ 
                  &  RGB    &  Sneden et~al. (\cite{Sneden04})      \\ 
NGC~6254 (M~10)   &  RGB    &  Kraft et~al. (\cite{Kraft95})       \\ 	     
NGC~6397          &  SGB+TO &  Carretta et~al. (\cite{Carretta05}) + Gratton et~al. (\cite{Gratton01}) \\ 
                  &  RGB    &  Norris \& Da Costa (\cite{Norris95}) \\ 
                  &  RGB    &  Carretta (\cite{Carretta94})           \\ 
NGC~6528          &  RHB    &  Carretta et~al. (\cite{Carretta01})    \\ 
NGC~6715 (M~54)   &  RGB    &  Brown et~al. (\cite{Brown99})       \\ 		     
NGC~6752          &  SGB+TO &  Carretta et~al. (\cite{Carretta05}) + Gratton et~al. (\cite{Gratton01}) \\ 
                  &  RGB    &  Yong et~al. (\cite{Yong03})        \\ 
                  &  RGB    &  Norris \& Da Costa (\cite{Norris95}) \\ 
                  &  RGB    &  Carretta (\cite{Carretta94})           \\ 
NGC~6838          &RGB+SGB+TO& Ramirez \& Cohen (\cite{Ramirez02})   \\ 		     
NGC~7006          &  RGB    &  Kraft et~al. (\cite{Kraft98})       \\ 
NGC~7078 (M~15)   &  RGB    &  Sneden et~al. (\cite{Sneden97})      \\ 		     
Pal 5             &  RGB    &  Smith et~al. (\cite{Smith02})       \\  
Pal 12            &  RGB    &  Cohen (\cite{Cohen04})              \\ 		     
Ter 7             &  RGB    &  Tautvaisiene et~al. (\cite{Tautvaisiene04})\\  
\hline
\end{tabular}}
\label{t:refertab}
\end{table}