\begin{thebibliography}{CDJM91}

\bibitem[CDJM91]{Danzig91sigcomm}
Ramon Careres, Peter~B. Danzig, Sugih Jamin, and Danny~J. Mitzel.
\newblock Characteristics of wide-area tcp/ip conversations.
\newblock In {\em Proceedings of the SIGCOMM '91 Symposium}, pages 101--112,
  September 1991.

\bibitem[NSR96]{ProgMan_3.3}
Network Systems Research Group, Department of Computer Science, University of
  Arizona.
\newblock {\em $x$-kernel Programmer's Manual (Version 3.3)}, January 1996.

\end{thebibliography}