@article{SF_1984__30_134729,
     author = {D.T. Huynh},
     title = {Properties of congruences on commutative monoids.},
     journal = {Semigroup forum},
     pages = {351--364},
     publisher = {mathdoc},
     volume = {30},
     year = {1984},
     zbl = {0548.20047},
     url = {http://geodesic.mathdoc.fr/item/SF_1984__30_134729/}
}