@article{GDZPPN00248787X, title = {Objects Dual to Subsemigroups of Groups.}, journal = {Monatshefte f\"ur Mathematik}, volume = {112}, year = {1991}, pages = {303-322}, zbl = {0737.22002}, url = {http://dml.mathdoc.fr/item/GDZPPN00248787X} }
Neeb, Karl-Hermann. Objects Dual to Subsemigroups of Groups.. Monatshefte für Mathematik, Tome 112 (1991) pp. 303-322. http://gdmltest.u-ga.fr/item/GDZPPN00248787X/