@article{GDZPPN001255770, title = {Generalized ideal elements in poe-semigroups.}, journal = {Semigroup forum}, volume = {24}, year = {1982}, pages = {213-222}, zbl = {0499.06012}, url = {http://dml.mathdoc.fr/item/GDZPPN001255770} }
Kehayopulu, N. Generalized ideal elements in poe-semigroups.. Semigroup forum, Tome 24 (1982) pp. 213-222. http://gdmltest.u-ga.fr/item/GDZPPN001255770/