@article{GDZPPN001248065, title = {Cayley functions.}, journal = {Semigroup forum}, volume = {2}, year = {1971}, pages = {349-358}, zbl = {0244.20069}, url = {http://dml.mathdoc.fr/item/GDZPPN001248065} }
Zupnik, D. Cayley functions.. Semigroup forum, Tome 2 (1971) pp. 349-358. http://gdmltest.u-ga.fr/item/GDZPPN001248065/