Corrado Böhm, Mariangiola Dezani-Ciancaglini. Combinatorial Problems, Combinator Equations and Normal Forms. In Jacques Loeckx, editor, Automata, Languages and Programming, 2nd Colloquium, University of Saarbrücken, July 29 - August 2, 1974, Proceedings. Volume 14 of Lecture Notes in Computer Science, pages 185-199, Springer, 1974.
Abstract is missing.