References
Text Books
[Koz] Dexter Kozen Automata and Computability Springer-Verlag[HMU] J Hopcroft, R. Motwani and J Ullman Introduction to Automata and Language Theory
Reference Books
[Sip] Michael Sipser Introduction to the theory of Computation Cengage Learning, 2013[LP] Harry Lewis and Christos Papadimitriou Elements of Theory of Computation. Prentice Hall.