@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},
     year = {1999},
     volume = {29},
     number = {2},
     url = {http://geodesic.mathdoc.fr/item/NSJOM_1999_29_2a_15/}
}