\begin{thebibliography}{2}
\expandafter\ifx\csname natexlab\endcsname\relax\def\natexlab#1{#1}\fi
\expandafter\ifx\csname url\endcsname\relax
  \def\url#1{{\tt #1}}\fi

\bibitem[Chow and Liu(1968)]{chow:68}
C.~K. Chow and C.~N. Liu.
\newblock Approximating discrete probability distributions with dependence
  trees.
\newblock {\em IEEE Transactions on Information Theory}, IT-14\penalty0
  (3):\penalty0 462--467, 1968.

\bibitem[Pearl(1988)]{pearl:88}
Judea Pearl.
\newblock {\em Probabilistic {R}easoning in {I}ntelligent {S}ystems: {N}etworks
  of {P}lausible {I}nference}.
\newblock Morgan Kaufman Publishers, San Mateo, CA, 1988.

\end{thebibliography}