@article{GDZPPN00124972X, title = {The multiplicative behavior of H.}, journal = {Semigroup forum}, volume = {7}, year = {1974}, pages = {74-81}, zbl = {0296.20030}, url = {http://dml.mathdoc.fr/item/GDZPPN00124972X} }
Grillet, Pierre Antoine. The multiplicative behavior of H.. Semigroup forum, Tome 7 (1974) pp. 74-81. http://gdmltest.u-ga.fr/item/GDZPPN00124972X/