TY  - JOUR
AU  - V. I. Amstislavskii
TI  - Extension of recursive hierarchies, and $R$-operations
JO  - Doklady Akademii Nauk
PY  - 1968
SP  - 1023
EP  - 1026
VL  - 180
IS  - 5
PB  - mathdoc
UR  - http://geodesic.mathdoc.fr/item/DAN_1968_180_5_a0/
LA  - ru
ID  - DAN_1968_180_5_a0
ER  -