TY  - JOUR
AU  - V. G. Kanovei
TI  - On the nonemptiness of classes in axiomatic set theory
JO  - Izvestiya. Mathematics 
PY  - 1978
SP  - 507
EP  - 535
VL  - 12
IS  - 3
PB  - mathdoc
UR  - http://geodesic.mathdoc.fr/item/IM2_1978_12_3_a4/
LA  - en
ID  - IM2_1978_12_3_a4
ER  -