@article{GDZPPN002409828, title = {Semigroups with No Non-Zero Nilpotent Elements.}, journal = {Mathematische Zeitschrift}, volume = {121}, year = {1971}, pages = {168-176}, zbl = {0212.35803}, url = {http://dml.mathdoc.fr/item/GDZPPN002409828} }
Adams, Donald H. Semigroups with No Non-Zero Nilpotent Elements.. Mathematische Zeitschrift, Tome 121 (1971) pp. 168-176. http://gdmltest.u-ga.fr/item/GDZPPN002409828/