@article{GDZPPN00126222X, title = {The existence of identity of orthodox semigroup rings.}, journal = {Semigroup forum}, volume = {46}, year = {1993}, pages = {27-31}, zbl = {0787.16024}, url = {http://dml.mathdoc.fr/item/GDZPPN00126222X} }
Li, F. The existence of identity of orthodox semigroup rings.. Semigroup forum, Tome 46 (1993) pp. 27-31. http://gdmltest.u-ga.fr/item/GDZPPN00126222X/