@article{GDZPPN001257323, title = {The translational degree of a semigroup.}, journal = {Semigroup forum}, volume = {30}, year = {1984}, pages = {331-350}, zbl = {0536.20039}, url = {http://dml.mathdoc.fr/item/GDZPPN001257323} }
Hildebrant, J.A. The translational degree of a semigroup.. Semigroup forum, Tome 30 (1984) pp. 331-350. http://gdmltest.u-ga.fr/item/GDZPPN001257323/