\end{itemize}
\end{itemize}
-\subsection{Total Current Spectroscopy}
+\subsection{Secondary Electron Spectroscopy}
+
+Secondary electron spectroscopy methods are a broad class of methods which investigate surface electron spectra through observing processes in which the surface electrons participate directly \cite{komolov}.
+
+Total Current Spectroscopy is a group of electron secondary
+
\begin{itemize}
\item
\item Total Current Spectroscopy methods measure the total current of secondary electrons as a function of primary electron energy.