@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/