providing proofs of the results. Martin Davis, Ron Sigal, Elaine J. Weyuker, Computability, complexity, and languages: fundamentals of theoretical computer science, 2nd ed., Academic Press, 1994, . Covers a wider range of topics than most other introductory books, including program semantics and quantification theory. Aimed at graduate students. Books on computability theory from the (wider) mathematical perspective Hartley Rogers, Jr (1987). Theory of Recursive Functions and Effective Computability, MIT Press. . Carl H. Smith, A recursive introduction to the theory of computation, Springer, 1994, . A shorter textbook suitable for graduate students in Computer Science. Historical perspective . External links Theory of Computation at MIT Theory of Computation at Harvard Computability Logic - A theory of interactive computation. The main web source on this subject.