\begin{thebibliography}{1}

\bibitem{structure}
Cold Spring~Harbor Laboratory.
\newblock Biologie cellulaire: l'adn.
\newblock {\em http://www.dnafb.org}, 2002.

\bibitem{replication}
www.nature.com.
\newblock structure.
\newblock {\em http://www.nature.com/nature/dna50/articles}, 2003.

\bibitem{adn}
www.wikipedie.com.
\newblock L'adn.
\newblock {\em encyclopédie en ligne Wikip\'edie}, 2004.

\end{thebibliography}
