Pythagorean Triples in Unification Theory of Nilpotent Rings. - Ruvim Lipyanski (FCT, 2001)

The unification type of the Pythagorean equation in varieties of nilpotent rings. - G. Belitskii; Ruvim Lipyanski (J. Symb. Comput., 2006)

Automorphisms of the Endomorphism Semigroup of a Free Associative Algebra. - Alexei Belov-Kanel; A. Berzins; Ruvim Lipyanski (Int. J. Algebra Comput., 2007)