Time for action – referencing items of a top list

We shall typeset a list of the most used packages for papers on the e-print archive site http://arXiv.org. Through the command \label, we will mark items that we can later refer to with the command \ref.

1. Create a new document with this code:

   \documentclass{book}
   \begin{document}
   \chapter{Statistics}
   \section{Most used packages on arXiv.org}\label{sec:packages}
   The Top Five packages, used on arXiv.org\footnote{according
   to the arXMLiv project\label{fn:project}}:
   \begin{enumerate}
     \item graphicx
     \item amssymb \label{item:amssymb}
     \item amsmath \label{item:amsmath}
     \item epsfig
     \item amsfonts
   \end{enumerate}
   \chapter{Mathematics}
   \emph{amsmath}, on position \ref{item:amsmath} of the top list
   in section~\ref{sec:packages} on page~\pageref{sec:packages},
   is indispensable to high-quality mathematical typesetting in
   \LaTeX.\emph{amssymb}, on position \ref{item:amssymb},
   provides a huge amount of math symbols.
   See also the footnote on page...