TY  - JOUR
AU  - Yu. I. Romanov
TI  - Comparison of the strength of certain $\Delta\Sigma$-operations in connection with the generalization of certain multiple separability theorems.
JO  - Izvestiâ vysših učebnyh zavedenij. Matematika
PY  - 1968
SP  - 80
EP  - 85
IS  - 3
PB  - mathdoc
UR  - http://geodesic.mathdoc.fr/item/IVM_1968_3_a10/
LA  - ru
ID  - IVM_1968_3_a10
ER  -