@article{GDZPPN002183269,
title = {Means over countable semigroups and almost-periodicity in l1.},
journal = {Journal f\"ur die reine und angewandte Mathematik},
volume = {229},
year = {1968},
pages = {194-206},
zbl = {0174.19201},
url = {http://dml.mathdoc.fr/item/GDZPPN002183269}
}
Günzler, Hans. Means over countable semigroups and almost-periodicity in l1.. Journal für die reine und angewandte Mathematik, Tome 229 (1968) pp. 194-206. http://gdmltest.u-ga.fr/item/GDZPPN002183269/