@article{GDZPPN001264966,
title = {Operators and products in the lattice of existence varieties of regular semigroups.},
journal = {Semigroup forum},
volume = {53},
year = {1996},
pages = {1-24},
zbl = {0854.20069},
url = {http://dml.mathdoc.fr/item/GDZPPN001264966}
}
Reilly, N.R.; Zhang, S. Operators and products in the lattice of existence varieties of regular semigroups.. Semigroup forum, Tome 53 (1996) pp. 1-24. http://gdmltest.u-ga.fr/item/GDZPPN001264966/