Voir la notice de l'article provenant de la source Novi sad journal of mathematics website
@article{NSJOM_1999_29_2a_15, author = {D. A. Romano}, title = {A left compatible coequality relation on a semigroup with apartness}, journal = {Novi Sad Journal of Mathematics}, pages = {221-234}, publisher = {mathdoc}, volume = {29}, number = {2}, year = {1999}, url = {http://geodesic.mathdoc.fr/item/NSJOM_1999_29_2a_15/} }
D. A. Romano. A left compatible coequality relation on a semigroup with apartness. Novi Sad Journal of Mathematics, Tome 29 (1999) no. 2. http://geodesic.mathdoc.fr/item/NSJOM_1999_29_2a_15/