TY  - JOUR
AU  - O.D. Kellog
TI  - On the existence and closure of sets of characteristic functions
JO  - Mathematische Annalen
PY  - 1922
SP  - 14
EP  - 17
VL  - 86
PB  - mathdoc
UR  - http://geodesic.mathdoc.fr/item/MAN_1922__86_158933/
ID  - MAN_1922__86_158933
ER  -