\begin{table}%t5
  \caption{Measured values of the linear bias for the VVDS and SDSS samples,
    within 3 stellar mass ranges (see text).} 
  \label{tab:bias}
%
  %%\centering
\par
  \small
\begin{tabular}{c c c c}
\hline
\hline
Sample &   $\log~(M/M_\odot)$  &          \multicolumn{2}{c}{$b(z)$}        \\
       &             & SDSS ($z\sim0.15$) & VVDS ($z\sim0.85$)  \\
\hline
  D2   & 9.5--10.0 &    $1.26\pm 0.03$  & $1.29\pm 0.10$	  \\
  D3   &10.0--10.5 &    $1.37\pm 0.03$  & $1.32\pm 0.12$	  \\
  D4   &10.5--11.0 &    $1.40\pm 0.03$  & $1.62\pm 0.18$	  \\
\hline
\end{tabular}
\end{table}