@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/