TY  - JOUR
AU  - S. M. Nikol'skii
TI  - The preservation of class under a differentiable mapping
JO  - Informatics and Automation
PY  - 1971
SP  - 327
EP  - 336
VL  - 112
PB  - mathdoc
UR  - http://geodesic.mathdoc.fr/item/TRSPY_1971_112_a20/
LA  - ru
ID  - TRSPY_1971_112_a20
ER  -