\begin{thebibliography}{}
 \bibitem{metnumalglin}{%
  Dario Bini, Milvio Capovani, Ornella Menchi,
  \emph{Metodi numerici per l'algebra lineare},
   Zanichelli}
 
 \bibitem{watkins}{%
 David S. Watkins,
 \emph{The Matrix Eigenvalue problem -- GR and Krylov Subspace Methods},
 SIAM}
 
 \bibitem{demmel}{%
  James W. Demmel,
  \emph{Applied Numeric Linear Algebra},
  SIAM
 }
 
 \bibitem{lshort}{%
  Tobias Oetiker, Hubert Partl, Irene Hyna and Elisabeth Schlegl,
  \emph{The not so short introduction to \LaTeXe, or \LaTeXe in 139 minutes},
  Scaricabile gratuitamente da Internet.
 }
 
 \bibitem{pgfmanual}{%
  Till Tantau,
 \emph{Tikz and PDF, Manual for version 1.10},
 Institut f\"ur Theoretische Informatik
 Universit\"at zu L\"ubeck,
 October 26, 2006, \verb-http://sourceforge.net/projects/pgf-
 }
\end{thebibliography}