Voir la notice de l'article provenant de la source Math-Net.Ru
@article{LJM_2005_18_a4, author = {P. K. Jakobsen and V. V. Lychagin}, title = {Universal semigroups}, journal = {Lobachevskii journal of mathematics}, pages = {107--125}, publisher = {mathdoc}, volume = {18}, year = {2005}, language = {en}, url = {http://geodesic.mathdoc.fr/item/LJM_2005_18_a4/} }
P. K. Jakobsen; V. V. Lychagin. Universal semigroups. Lobachevskii journal of mathematics, Tome 18 (2005), pp. 107-125. http://geodesic.mathdoc.fr/item/LJM_2005_18_a4/