Voir la notice de l'article provenant de la source Czech Digital Mathematics Library
@article{MASLO_1962__12_3_a5, author = {Wiegold, James}, title = {Semigroup {Coverings} of {Groups.} {II.}}, journal = {Mathematica slovaca}, pages = {217--223}, publisher = {mathdoc}, volume = {12}, number = {3}, year = {1962}, mrnumber = {0158946}, zbl = {0161.02101}, language = {en}, url = {http://geodesic.mathdoc.fr/item/MASLO_1962__12_3_a5/} }
Wiegold, James. Semigroup Coverings of Groups. II.. Mathematica slovaca, Tome 12 (1962) no. 3, pp. 217-223. http://geodesic.mathdoc.fr/item/MASLO_1962__12_3_a5/