@article{SF_1974__7_134017,
     author = {T.E. Hall},
     title = {On congruences on finite semigroups.},
     journal = {Semigroup forum},
     pages = {369--371},
     publisher = {mathdoc},
     volume = {7},
     year = {1974},
     zbl = {0276.20054},
     url = {http://geodesic.mathdoc.fr/item/SF_1974__7_134017/}
}