@article{GDZPPN001255894,
title = {The group of units as a maximal inverse subsemigroup.},
journal = {Semigroup forum},
volume = {24},
year = {1982},
pages = {381-382},
zbl = {0499.20042},
url = {http://dml.mathdoc.fr/item/GDZPPN001255894}
}
Baird, B. The group of units as a maximal inverse subsemigroup.. Semigroup forum, Tome 24 (1982) pp. 381-382. http://gdmltest.u-ga.fr/item/GDZPPN001255894/