\begin{thebibliography}{99}

\bibitem{shapiro} % OK
L. Sterling and E. Shapiro, {\it The Art of Prolog: Advanced Programming
Techniques}, {\small MIT} Press, 1986.

\bibitem{fischer} % OK
C.N. Fischer and R.J. LeBlanc, Jr., {\it Crafting a Compiler},
Benjamin/Cummings, 1988.

\end{thebibliography}
