Additional bibliography for study
- John Hopcroft, Rajeev Motwani, Jeffrey Ullman, Introduction to Automata Theory, Languages, and Computation, Addison-Wesley, 3rd edition 2007.
- Juraj Hromkovic, Theoretical Computer Science, Texts in Theoretical Computer Science, EATCS Series, Springer, 2004.
- Harry Lewis, Christos Papadimitriou, Elements of the Theory of Computation, Prentice-Hall Inc., 2nd edition 1998.
- Grzegorz Rozenberg, Arto Salomaa eds., Handbook of Formal Languages, volumes 1-3, Springer-Verlag, Berlin, 1997.