1. Arvind, V., Kurur, P.: Graph isomorphism is in SPP. In: Proceedings 43rd Symposium on Foundations of Computer Science, pp. 743–750. IEEE Computer Society Press, Los Alamitos (2002)
2. Agrawal, M., Thierauf, T.: The formula isomorphism problem. SIAM Journal on Computing 30(3), 990–1009 (2000)
3. Lecture Notes in Computer Science;E. Böhler,2002
4. Bulatov, A., Krokhin, A., Jeavons, P.: The complexity of maximal constraint languages. In: Proceedings 33rd Symposium on Theory of Computing, pp. 667–674. ACM Press, New York (2001)
5. Borchert, B., Ranjan, D., Stephan, F.: On the computational complexity of some classical equivalence relations on Boolean functions. Theory of Computing Systems 31, 679–693 (1998)