@article{10_4064_cm_25_2_211_224,
     author = {C. S. Hoo and K. P. Shum},
     title = {On the nilpotent elements of semigroups},
     journal = {Colloquium Mathematicum},
     pages = {211--224},
     publisher = {mathdoc},
     volume = {25},
     number = {2},
     year = {1972},
     doi = {10.4064/cm-25-2-211-224},
     language = {en},
     url = {http://geodesic.mathdoc.fr/articles/10.4064/cm-25-2-211-224/}
}