@article{GDZPPN002307693,
title = {Invariant Means via the Ultrapower.},
journal = {Mathematische Annalen},
volume = {201},
year = {1973},
pages = {71-76},
zbl = {0235.43001},
url = {http://dml.mathdoc.fr/item/GDZPPN002307693}
}
Adler, Andrew; Hamilton, James. Invariant Means via the Ultrapower.. Mathematische Annalen, Tome 201 (1973) pp. 71-76. http://gdmltest.u-ga.fr/item/GDZPPN002307693/