@article{GDZPPN001255533,
title = {Identities valid globally in semigroups.},
journal = {Semigroup forum},
volume = {24},
year = {1982},
pages = {263-270},
url = {http://dml.mathdoc.fr/item/GDZPPN001255533}
}
Ljapin, E.D. Identities valid globally in semigroups.. Semigroup forum, Tome 24 (1982) pp. 263-270. http://gdmltest.u-ga.fr/item/GDZPPN001255533/