--- a/document/root.tex	Sat Dec 29 20:17:57 2012 +0000
+++ b/document/root.tex	Sun Dec 30 14:58:48 2012 +0000
@@ -80,8 +80,8 @@
 \input{session}
 
 % optional bibliography
-%\bibliographystyle{abbrv}
-%\bibliography{root}
+\bibliographystyle{abbrv}
+\bibliography{root}
 
 \end{document}