@article{GDZPPN001249479, title = {A generalization of Green's relations in semigroups.}, journal = {Semigroup forum}, volume = {7}, year = {1974}, pages = {74-85}, zbl = {0276.20052}, url = {http://dml.mathdoc.fr/item/GDZPPN001249479} }
Márki, L.; Steinfeld, O. A generalization of Green's relations in semigroups.. Semigroup forum, Tome 7 (1974) pp. 74-85. http://gdmltest.u-ga.fr/item/GDZPPN001249479/