-systems of unary algebras. I: On maximal and greatest -classes of the direct product of unary algebras
Radicals and their left ideal analogues in a semigroup
RC-commutative ...-semigroups.
Regular semirings.
Reidemeister- Schreier type rewriting for semigroups.
Relationship between the inverse transversals of a regular semigroup.
Remark on one-sided -ideals of semigroups
Remark on partially ordered sets, universal algebras and semigroups
Remarks on 0-minimal quasi-ideals in semigroups.
Representations of semigroups of idempotents
Right compositions of semigroups
Right Prime Ideals and Maximal Right Ideals in Semigroups