Latex Latex skills memo []

Reference section

\section{Chapter1}
\label{sec:chapter1} % define label

\section{Chaprter2}
Chapter1 can be find in Section \ref{sec:chapter1}.

Subgraph

\begin{figure}[!t]
    \centering
    \subfloat[sublabel_1]{
        \includegraphics[width=3.5in]{fig_1.pdf}%
        \label{fig:fig_1}
        }
    \hfil
    \subfloat[sublabel_2]{
        \includegraphics[width=3.5in]{fig_2.pdf}%
        \label{fig:fig_2}
        }
    \caption{Description of the figures.}
    \label{fig:fig_1_2}
\end{figure}