@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/