\begin{table}%t1
\caption{\label{table: sec-per-nod}Secular resonances involving the perihelion, the 
node, and combinations of perihelion and node of the asteroid.  
The first, third, and fifth columns report the resonant argument 
in terms of the planetary frequencies, 
and the second, fourth, and sixth we give the names we use in this article.}
%\centering
\par
\begin{tabular}{cccccc}
\hline
  \hline     
Perihelion res.              &  Names  &  Node res. & Names & Perihelion and node res.& Names\\
\hline
  $g - 2g_5 - g_6 + 2g_7$      & ${\gamma}_1$     &  $s -s_6 + g_6 - g_7$  & ${\sigma}_1$    & $2g - g_6 - g_4 + s - s_4$ & ${\psi}_1$  \\
$2g - 2g_6 +g_5 - g_4$       & ${\gamma}_2$     &  $s -s_6 - g_5 + g_6$  & ${\sigma}_2$    & $2g - g_6 - g_7 + s - s_7$ & ${\psi}_2$  \\
$2g - 2g_6 + g_7 - g_4$      & ${\gamma}_{3a}$  &  $s - 2s_6 + s_7$      & ${\sigma}_3$    & $2g - g_5 - g_6 + s - s_7$ & ${\psi}_3$  \\
$2g - 3g_6 + g_4$            & ${\gamma}_{3b}$  &  $s - 2s_6 + s_4$      & ${\sigma}_4$    & $2(g-g_6) + s - s_6$       & ${\psi}_4$,$z_2$\\
$g + 2g_5 - 3g_4$            & ${\gamma}_4$     &  $s - s_6 - g_7 + g_4$ & ${\sigma}_{5a}$ & $g - g_4 + 2s - 2s_6$      & ${\psi}_5$  \\
$g + g_5 + g_7 - 3g_4$       & ${\gamma}_{5a}$  &  $s - s_6 + g_6 - g_4$ & ${\sigma}_{5b}$ & $g - g_5 + 2s- s_6 - s_4$  & ${\psi}_6$  \\
$g + g_5 - g_6 - g_4$        & ${\gamma}_{5b}$  &  $s - s_4 - g_5 + g_6$ & ${\sigma}_{6}$  & $g - g_7 + 2s - s_6 - s_4$ & ${\psi}_7$  \\
$g + g_5 - 2g_6 - g_7 + g_4$ & ${\gamma}_{5c}$  &  $s -s_4 + g_6 - g_7$  & ${\sigma}_7$    & $g - g_5 + 2s- 2s_6$       & ${\psi}_8$  \\
$g + 2g_7 - 3g_4$            & ${\gamma}_{6a}$ &                        &                 & $g - g_7 +2s - 2s_6$       & ${\psi}_9$  \\
$g - g_6 + g_7 - g_4$        & ${\gamma}_{6b}$  &                        &                 &                            &      \\
$g - 2g_6 + g_4$             & ${\gamma}_{6c}$  &                        &                 &                            &      \\
\par
\hline
\end{tabular}
\end{table}