@article{GDZPPN001262971,
title = {Adjan's theorem and conjugacy in semigroups.},
journal = {Semigroup forum},
volume = {46},
year = {1993},
pages = {299-304},
zbl = {0797.20043},
url = {http://dml.mathdoc.fr/item/GDZPPN001262971}
}
Goldstein, R.; Teymouri, J. Adjan's theorem and conjugacy in semigroups.. Semigroup forum, Tome 46 (1993) pp. 299-304. http://gdmltest.u-ga.fr/item/GDZPPN001262971/