The following publications are possibly variants of this publication:
- The Theory of Idempotent Semigroups is of Unification Type ZeroFranz Baader. JAR, 2(3):283-286, 1986.
- Unification TheoryJörg H. Siekmann. ecai 1986: 365-400
- Unification TheoryJörg H. Siekmann. JSC, 7(3/4):207-274, 1989.
- Unification theoryJörg H. Siekmann. dss, 6(4):315-337, 1990. [doi]
- Unification TheoryFranz Baader, Wayne Snyder. In John Alan Robinson, Andrei Voronkov, editors, Handbook of Automated Reasoning (in 2 volumes). pages 445-532, Elsevier and MIT Press, 2001.
- Unification TheoryFranz Baader. iwwert 1992: 151-170