
\begin{thebibliography}{1}

\bibitem{PPML}
P.~Borras.
\newblock {\em {PPML} Reference Manual \& Compiler Implementation}.
\newblock Sema Group, INRIA Sophia-Antipolis, 2004 Route des Lucioles, 06565
  Valbonne CEDEX, France, June 1989.
\newblock Appears in {\it The CENTAUR Reference Manual}. Contact: CENTAUR
  Distribution (centaur@mirsa.inria.fr).

\bibitem{description} % OK
{\small DSTO} and {\small SRI} International, 
{\it The HOL System: DESCRIPTION}, (1991).

\end{thebibliography}


