@article{GDZPPN001256866, title = {Conjugacy in monoids.}, journal = {Semigroup forum}, volume = {30}, year = {1984}, pages = {223-240}, zbl = {0551.20044}, url = {http://dml.mathdoc.fr/item/GDZPPN001256866} }
Otto, F. Conjugacy in monoids.. Semigroup forum, Tome 30 (1984) pp. 223-240. http://gdmltest.u-ga.fr/item/GDZPPN001256866/