1. Apt, K.R., van Emden, M.H.: Contributions to the theory of logic programming. Journal of the ACM 29(3), 841–862 (1982)
2. Baumgartner, P., Furbach, U.: Calculi for disjunctive logic programming. In: Maluszynski, J. (ed.) Proc. of ILPS 1997, pp. 229–243. The MIT Press, Cambridge (1997)
3. Lecture Notes in Computer Science;S. Brass,1992
4. Chang, C.-L., Lee, R.C.-T.: Symbolic Logic and Mechanical Theorem Proving. Academic Press, London (1973)
5. Green, C.C.: Theorem proving by resolution as basis for question-answering systems. Machine Intelligence 4, 183–205 (1969)