@article{GDZPPN001250264, title = {Ideal extensions of irreductive semigroups.}, journal = {Semigroup forum}, volume = {7}, year = {1974}, pages = {216-240}, zbl = {0293.20050}, url = {http://dml.mathdoc.fr/item/GDZPPN001250264} }
Schein, B.M.; Gluskin, L.M. Ideal extensions of irreductive semigroups.. Semigroup forum, Tome 7 (1974) pp. 216-240. http://gdmltest.u-ga.fr/item/GDZPPN001250264/