Voir la notice de l'article provenant de la source European Digital Mathematics Library
@article{MZ_1976__149_172391, author = {Neil Hindman and W.W. Comfort}, title = {Refining {Families} for {Ultrafilters.}}, journal = {Mathematische Zeitschrift}, pages = {189--200}, publisher = {mathdoc}, volume = {149}, year = {1976}, zbl = {0314.54039}, url = {http://geodesic.mathdoc.fr/item/MZ_1976__149_172391/} }
Neil Hindman; W.W. Comfort. Refining Families for Ultrafilters.. Mathematische Zeitschrift, Tome 149 (1976), pp. 189-200. http://geodesic.mathdoc.fr/item/MZ_1976__149_172391/