@article{GDZPPN00223758X, title = {Logarithmic Density and Measures on Semigroups.}, journal = {Manuscripta mathematica}, volume = {91}, year = {1996}, pages = {307-318}, zbl = {0860.11005}, url = {http://dml.mathdoc.fr/item/GDZPPN00223758X} }
Ruzsa, Imre Z. Logarithmic Density and Measures on Semigroups.. Manuscripta mathematica, Tome 91 (1996) pp. 307-318. http://gdmltest.u-ga.fr/item/GDZPPN00223758X/