@article{GDZPPN00126043X, title = {Strongly differentiable monoids with smooth boundary.}, journal = {Semigroup forum}, volume = {40}, year = {1990}, pages = {363-378}, zbl = {0699.22003}, url = {http://dml.mathdoc.fr/item/GDZPPN00126043X} }
Anderson, M. Strongly differentiable monoids with smooth boundary.. Semigroup forum, Tome 40 (1990) pp. 363-378. http://gdmltest.u-ga.fr/item/GDZPPN00126043X/