@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/