TY  - JOUR
AU  - E. G. Pytkeev
AU  - A. G. Chentsov
TI  - Open ultrafilters and separability with the use of the operation of closure
JO  - Trudy Instituta matematiki i mehaniki
PY  - 2016
SP  - 212
EP  - 225
VL  - 22
IS  - 3
PB  - mathdoc
UR  - http://geodesic.mathdoc.fr/item/TIMM_2016_22_3_a21/
LA  - ru
ID  - TIMM_2016_22_3_a21
ER  -