\begin{thebibliography}{Coh93} \bibitem[Bre89]{Bressoud89} D.~M. Bressoud. \newblock {\em Factorization and Primality Testing}. \newblock Springer-Verlag, 1989. \bibitem[Bre96]{Brent96} R.~P. Brent. \newblock Factorization of the tenth and eleventh {F}ermat numbers, 1996. \newblock \href {ftp://ftp.comlab.ox.ac.uk/pub/Documents/techpapers/Richard.Brent/rpb161tr.d% vi.gz} {\texttt{ftp://ftp.comlab.ox.ac.uk/}\discretionary {}{}{}\texttt{pub/}\discretionary {}{}{}\texttt{Documents/}\discretionary {}{}{}\texttt{techpapers/}\discretionary {}{}{}\texttt{Richard.Brent/}\discretionary {}{}{}\texttt{rpb161tr.dvi.gz}}. \bibitem[Bre04]{Brent04} R.~P. Brent. \newblock Factor tables, 2004. \newblock \href {http://web.comlab.ox.ac.uk/oucl/work/richard.brent/factors.html} {\texttt{http://web.comlab.ox.ac.uk/}\discretionary {}{}{}\texttt{oucl/}\discretionary {}{}{}\texttt{work/}\discretionary {}{}{}\texttt{richard.brent/}\discretionary {}{}{}\texttt{factors.html}}. \bibitem[Coh93]{Cohen93} H.~Cohen. \newblock {\em A Course in Computational Algebraic Number Theory}. \newblock Springer-Verlag, 1993. \bibitem[LN07]{GAPDoc} F.~L{\"u}beck and M.~Neunh{\"o}ffer. \newblock {\em {GAPDoc (Version 1.0)}}. \newblock RWTH Aachen, 2007. \newblock GAP package, \href {http://www.gap-system.org/Packages/gapdoc.html} {\texttt{http://www.gap-system.org/}\discretionary {}{}{}\texttt{Packages/}\discretionary {}{}{}\texttt{gapdoc.html}}. \end{thebibliography}