Voir la notice de l'article provenant de la source European Digital Mathematics Library
@article{SF_1975__11_134139, author = {Thomas Nordah1}, title = {CANCELLATIVE {SEMIGROUPS} {WITH} {NON-EMPTY} {CENTER.}}, journal = {Semigroup forum}, pages = {170--177}, publisher = {mathdoc}, volume = {11}, year = {1975}, language = {en}, url = {http://geodesic.mathdoc.fr/item/SF_1975__11_134139/} }
Thomas Nordah1. CANCELLATIVE SEMIGROUPS WITH NON-EMPTY CENTER.. Semigroup forum, Tome 11 (1975), pp. 170-177. http://geodesic.mathdoc.fr/item/SF_1975__11_134139/