TY  - JOUR
AU  - Yu. V. Egorov
TI  - On pseudo-differential operators of the principal type
JO  - Doklady Akademii Nauk
PY  - 1966
SP  - 778
EP  - 780
VL  - 171
IS  - 4
PB  - mathdoc
UR  - http://geodesic.mathdoc.fr/item/DAN_1966_171_4_a3/
LA  - ru
ID  - DAN_1966_171_4_a3
ER  -