Voir la notice de l'article provenant de la source Czech Digital Mathematics Library
@article{MASLO_1970__20_2_a2, author = {Kraj\v{n}\'akov\'a, Dorota}, title = {On {Dual} {Semigroups}}, journal = {Mathematica slovaca}, pages = {87--91}, publisher = {mathdoc}, volume = {20}, number = {2}, year = {1970}, mrnumber = {0308298}, zbl = {0206.30403}, language = {en}, url = {http://geodesic.mathdoc.fr/item/MASLO_1970__20_2_a2/} }
Krajňáková, Dorota. On Dual Semigroups. Mathematica slovaca, Tome 20 (1970) no. 2, pp. 87-91. http://geodesic.mathdoc.fr/item/MASLO_1970__20_2_a2/