\begin{thebibliography}{1}

\bibitem{GARE82}
M.R. Garey and D.S. Johnson.
\newblock {\em Computers and Intractability: A Guide to the Theory of
  {NP-Completeness}}.
\newblock W.H. Freeman and Company, New York, 1982.

\bibitem{GOLD89}
D.E. Goldberg.
\newblock {\em Genetic Algorithms in Search, Optimization, and Machine
  Learning}.
\newblock Addison-Wesley, Reading, MA, 1989.

\bibitem{Horowitz}
L.S. Horowitz and F.~Sahni.
\newblock {\em Fundamentals of Data Structures in Pascal}.
\newblock Computer Science Press, 1987.

\end{thebibliography}
