On weakly commutative poe-semigroups. N. Kehayopulu; Kiriakuli P.; S. Hanumantha Rao; P. Lakshmi — 1990 Semigroup forum
The least semilattice of groups congruence on an eventually regular semigroup. P. Lakshmi; Hanumantha S. Rao — 1991 Semigroup forum