TY  - JOUR
AU  - Yu. L. Ershov
TI  - Hereditarily effective operations
JO  - Algebra i logika
PY  - 1976
SP  - 642
EP  - 654
VL  - 15
IS  - 6
PB  - mathdoc
UR  - http://geodesic.mathdoc.fr/item/AL_1976_15_6_a3/
LA  - ru
ID  - AL_1976_15_6_a3
ER  -