1. Andrews, P.B.,, "Resolution with Merging", Journal of the Association for Computing Machinery, 15, 367–381, July 1968.
2. Brown, T.C. Jr., "Resolution with Covering strategies and Equality Theory", internal memorandum, California Institute of Technology, 1968.
3. Chang, C.L., "Renamable Paramodulation for Automatic Theorem-Proving with Equality", internal memorandum, National Institutes of Health, Bethesda, Maryland, 1969.
4. Darlington, J.L., "Automatic Theorem-Proving with Equality Substitutions and Mathematical Induction", Machine Intelligence 3, edited D. Michie, Edinburgh University Press, 113–127, 1968.
5. Hayes, P.J., and Kowalski, R., "Semantic Trees in Automatic Theorem-Proving", Machine Intelligence 4, edited B. Meltzer and D. Michie, Edinburgh University Press, 1969.