我有下表:
\begin{table}[ht]\footnotesize
\centering
\begin{tabular}{|lp{1cm}p{1cm}}
\hline
\begin{sideways}Parameter\end{sideways} &
\begin{sideways}Long header name ... \end{sideways} &
\begin{sideways}Long header..\end{sideways} \\ \hline
\end{tabular}
\caption{Summary}
\label{tab:summary}
\end{table}
如何打破侧向标题,以便可以占据两行?