@article{GDZPPN001251856,
title = {Sch\"utzenberger groups and Chebyshev polynomials.},
journal = {Semigroup forum},
volume = {12},
year = {1976},
pages = {301-306},
zbl = {0354.20052},
url = {http://dml.mathdoc.fr/item/GDZPPN001251856}
}
Magill, K.D. jr.; Schanuel, S. Schützenberger groups and Chebyshev polynomials.. Semigroup forum, Tome 12 (1976) pp. 301-306. http://gdmltest.u-ga.fr/item/GDZPPN001251856/