%0 Journal Article
%A O.D. Kellog
%T On the existence and closure of sets of characteristic functions
%J Mathematische Annalen
%D 1922
%P 14-17
%V 86
%I mathdoc
%U http://geodesic.mathdoc.fr/item/MAN_1922__86_158933/
%F MAN_1922__86_158933