@article{MZ_1971__123_171628,
     author = {Donald H. Adams},
     title = {Semigroups with {No} {Non-Zero} {Nilpotent} {Elements.}},
     journal = {Mathematische Zeitschrift},
     pages = {168--176},
     publisher = {mathdoc},
     volume = {123},
     year = {1971},
     zbl = {0212.35803},
     url = {http://geodesic.mathdoc.fr/item/MZ_1971__123_171628/}
}