@article{GDZPPN001261282, title = {On a problem in poe-semigroups.}, journal = {Semigroup forum}, volume = {43}, year = {1991}, pages = {260-262}, zbl = {0732.06008}, url = {http://dml.mathdoc.fr/item/GDZPPN001261282} }
Murty, P.V. Ramana; Rao, S. Hanumantha. On a problem in poe-semigroups.. Semigroup forum, Tome 43 (1991) pp. 260-262. http://gdmltest.u-ga.fr/item/GDZPPN001261282/