\begin{table}%t6
%\centering
\par
\caption {\label{FITS}Linear least-square fit between oxygen and other elements in bulge
PNe, bulge giants and in the blue compact galaxies studied by Izotov et~al. 
(\cite{Izotov06}): $y=ax+b$ (and one-sigma uncertainties). 
}
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\hline\hline
\par
   & $a$ & $b$ & $\chi2$ & $q$ \\
\par
\hline
\par
Bulge PNe\\
\par
\hline
\par
log~(Ne/H) vs. log~(O/H)  & 1.34 $\pm$ 0.02 &  --3.58 $\pm$ 0.17 & 208 &
5.79 $\times$ 10$^{-15}$ \\
\par
log~(Ar/H) vs. log~(O/H) & 1.31 $\pm$ 0.02 &  --4.93 $\pm$ 0.13 & 554 &
4.11 $\times$ 10$^{-61}$\\
\par
log~(S/H) vs. log~(O/H)  & 1.40 $\pm$ 0.02 &  --5.18 $\pm$ 0.15 & 425 &
1.36 $\times$ 10$^{-44}$\\
\par
log~(N/H) vs. log~(O/H)  & 2.27 $\pm$ 0.09 & --11.23 $\pm$ 0.27 & 836  &
4.37 $\times$ 10$^{-115}$\\
\par
\hline
\par
Stars & & & & \\
\par
\hline
\par
log~(N/H) vs. log~(O/H) & 1.32            & --3.49             & 34.4  & -- \\
\par
log~(Si/H) vs. log~(O/H) & 1.22            & --3.24             & 6.71  & -- \\
\par
log~(Mg/H) vs. log~(O/H) & 1.02            & --1.26             & 102.  & -- \\
\par
\hline
\par
H II Regions (Izotov et~al. \cite{Izotov06}) & & & & \\
\par
\hline
\par
log~(Ne/H) vs. log~(O/H) & 1.09 $\pm$ 0.01 & --1.45 $\pm$ 0.05 & --  & -- \\
\par
log~(Ar/H) vs. log~(O/H) & 1.04 $\pm$ 0.01 & --2.71 $\pm$ 0.08 & -- & -- \\
\par
log~(S/H) vs. log~(O/H) & 0.97 $\pm$  0.01 & --1.51 $\pm$ 0.07 & -- & --\\
\hline
\end{tabular}
\end{table}