\subsubsection{This is the first subsubsection from file \texttt{include5.tex}}
\label{section51}

Here is a reference to the next subsubsection \ref{section52} 
and one in the previous input file \ref{section42}.  Notice
that the reference to the next subsubsection is 3.0.5 and not
3.0.1.  This shows sections reset subsection counters, but not
subsubsection counters.  How bizarre!

\subsubsection{This is the second subsubsection from file \texttt{include5.tex}}
\label{section52}

Furthermore,
after reading the \LaTeX{} book, I see that \verb#\include# 
files will all start on a new page.  This is not the case for
\verb#\input# files.  Here is a reference to the previous subsubsection \ref{section51}.
Here is a reference to the first subsection from \texttt{include1.tex}
\ref{section11}.
