@article{GDZPPN001258834,
title = {Bicharacters of semigroups.},
journal = {Semigroup forum},
volume = {33},
year = {1986},
pages = {253-264},
zbl = {0625.20055},
url = {http://dml.mathdoc.fr/item/GDZPPN001258834}
}
Lesokhin, M.M.; Popyrin, A. V. Bicharacters of semigroups.. Semigroup forum, Tome 33 (1986) pp. 253-264. http://gdmltest.u-ga.fr/item/GDZPPN001258834/