@article{GDZPPN001260847, title = {The congruence class of an idempotent in a regular semigroup.}, journal = {Semigroup forum}, volume = {43}, year = {1991}, pages = {121-124}, zbl = {0741.20047}, url = {http://dml.mathdoc.fr/item/GDZPPN001260847} }
Adams, M.E.; Gould, M.; Tschantz, S.T. The congruence class of an idempotent in a regular semigroup.. Semigroup forum, Tome 43 (1991) pp. 121-124. http://gdmltest.u-ga.fr/item/GDZPPN001260847/