@article{GDZPPN001251538, title = {Semilattices of proper inverse semigroups.}, journal = {Semigroup forum}, volume = {12}, year = {1976}, pages = {29-36}, zbl = {0337.20027}, url = {http://dml.mathdoc.fr/item/GDZPPN001251538} }
Hardy, D.W.; Tirasupa, Y. Semilattices of proper inverse semigroups.. Semigroup forum, Tome 12 (1976) pp. 29-36. http://gdmltest.u-ga.fr/item/GDZPPN001251538/