@article{GDZPPN00124812X, title = {Maximal semigroup orbits.}, journal = {Semigroup forum}, volume = {4}, year = {1972}, pages = {61-68}, zbl = {0253.22001}, url = {http://dml.mathdoc.fr/item/GDZPPN00124812X} }
Borrego, J.T.; Devun, E.E. Maximal semigroup orbits.. Semigroup forum, Tome 4 (1972) pp. 61-68. http://gdmltest.u-ga.fr/item/GDZPPN00124812X/