@article{GDZPPN001254111, title = {Lattice isomorphisms of commutative relatively free semigroups.}, journal = {Semigroup forum}, volume = {20}, year = {1980}, pages = {189-226}, zbl = {0487.20037}, url = {http://dml.mathdoc.fr/item/GDZPPN001254111} }
Ovsyannikov, A.J. Lattice isomorphisms of commutative relatively free semigroups.. Semigroup forum, Tome 20 (1980) pp. 189-226. http://gdmltest.u-ga.fr/item/GDZPPN001254111/