@article{GDZPPN001251708, title = {On exposed semigroup homomorphisms.}, journal = {Semigroup forum}, volume = {12}, year = {1976}, pages = {189-204}, zbl = {0355.20072}, url = {http://dml.mathdoc.fr/item/GDZPPN001251708} }
Fuchssteiner, B. On exposed semigroup homomorphisms.. Semigroup forum, Tome 12 (1976) pp. 189-204. http://gdmltest.u-ga.fr/item/GDZPPN001251708/