TY  - JOUR
AU  - I. D. Stupina
TI  - Certain properties of $R$- and $R^c$-operations
JO  - Doklady Akademii Nauk
PY  - 1969
SP  - 1010
EP  - 1013
VL  - 188
IS  - 5
PB  - mathdoc
UR  - http://geodesic.mathdoc.fr/item/DAN_1969_188_5_a12/
LA  - ru
ID  - DAN_1969_188_5_a12
ER  -