1
Garey MR, Johnson DS. Computers and intractability: a guide to the theory of NP-completeness. New York: : W. H. Freeman 1979.
2
Rayward-Smith VJ. A first course in computability. Oxford: : Blackwell Scientific 1986.
3
Harry R. Lewis. Elements of the theory of computation. Upper Saddle River, N.J: : Prentice-Hall 1998.
4
Sipser M. Introduction to the theory of computation. 3rd ed., International ed. Australia: : Cengage Learning 2013.
5
Hopcroft JohnE, Motwani R, Ullman JD. Introduction to Automata Theory, Languages, and Computation. Pearson Education 2003.