TY  - JOUR
AU  - G. G. Kazaryan
AU  - V. N. Markaryan
TI  - Hypoellipticity criteria in terms of power and strength of operators
JO  - Informatics and Automation
PY  - 1979
SP  - 128
EP  - 142
VL  - 150
PB  - mathdoc
UR  - http://geodesic.mathdoc.fr/item/TRSPY_1979_150_a7/
LA  - ru
ID  - TRSPY_1979_150_a7
ER  -