TY  - JOUR
AU  - A. I. Mal'tsev
TI  - On derivative operations and predicates
JO  - Doklady Akademii Nauk
PY  - 1957
SP  - 24
EP  - 27
VL  - 116
IS  - 1
PB  - mathdoc
UR  - http://geodesic.mathdoc.fr/item/DAN_1957_116_1_a5/
LA  - ru
ID  - DAN_1957_116_1_a5
ER  -