@article{GDZPPN001247182, title = {On semigroup's admitting ring structure.}, journal = {Semigroup forum}, volume = {1}, year = {1970}, pages = {189-208}, zbl = {0209.32502}, url = {http://dml.mathdoc.fr/item/GDZPPN001247182} }
Peinado, R.E. On semigroup's admitting ring structure.. Semigroup forum, Tome 1 (1970) pp. 189-208. http://gdmltest.u-ga.fr/item/GDZPPN001247182/