@article{PPN362162808_0014+dmdlog21, title = {Congruence relations on left canonic semigroups.}, journal = {Semigroup forum}, volume = {14}, year = {1977}, pages = {175-184}, zbl = {0396.20043}, url = {http://dml.mathdoc.fr/item/PPN362162808_0014+dmdlog21} }
Yoh, R.W. Congruence relations on left canonic semigroups.. Semigroup forum, Tome 14 (1977) pp. 175-184. http://gdmltest.u-ga.fr/item/PPN362162808_0014+dmdlog21/