Voir la notice de l'article provenant de la source Math-Net.Ru
@article{DM_2012_24_4_a1, author = {S. S. Marchenkov}, title = {Definition of positively closed classes by endomorphism semigroups}, journal = {Diskretnaya Matematika}, pages = {19--26}, publisher = {mathdoc}, volume = {24}, number = {4}, year = {2012}, language = {ru}, url = {http://geodesic.mathdoc.fr/item/DM_2012_24_4_a1/} }
S. S. Marchenkov. Definition of positively closed classes by endomorphism semigroups. Diskretnaya Matematika, Tome 24 (2012) no. 4, pp. 19-26. http://geodesic.mathdoc.fr/item/DM_2012_24_4_a1/