\begin{thebibliography}{HMU01}

\bibitem[HMU01]{Hop1}
J.~E. Hopcroft, R.~Motwani, and J.~D. Ullman.
\newblock {\em {``Introduction to Automata Theory, Language, and
  Computation''}}.
\newblock Addison--Wesley, 2nd edition edition, 2001.

\end{thebibliography}
