Garey, Michael R., and David S. Johnson, Computers and Intractability: A Guide to the Theory of NP-Completeness (W. H. Freeman, 1979)
Harry R. Lewis, Elements of the Theory of Computation (Prentice-Hall, 1998)
Hopcroft, John. E, Rajeev Motwani, and Jeffrey D Ullman, Introduction to Automata Theory, Languages, and Computation (Pearson Education, 2003)
Rayward-Smith, V. J., A First Course in Computability (Blackwell Scientific, 1986), Computer science texts
Sipser, Michael, Introduction to the Theory of Computation, 3rd ed., International ed (Cengage Learning, 2013)
