1. Mathematical Theory of Computation;Manna,1974
2. Testing for software reliability;Brown;Intern. Conf. in Reliable Software,1975
3. The testing of computer software;Llewelyn;Conf. on Software Engineering,1969
4. R.A. DeMillo, R.J. Lipton, A.J. Perlis, Social processes and proofs of theorems and programs, Fourth ACM Symposium in Principles of Programming Languages (to appear in CACM).
5. Algebraic program testing;Howden,1976