@inbook{Hopcroft-Ullman79,
  author	= {Hopcroft, J. E. and Ullman, J. D.},
  year		= {1987},
  title		= {Introduction to Automata Theory, Languages, and Computation},
  chapter	= {2},
  pages		= {13--45},
  publisher	= {Addison-Wesley Publishing Company}
}