TY  - JOUR
AU  - Yu. V. Egorov
TI  - Conditions for the local solvability of equations of principal type
JO  - Trudy Matematicheskogo Instituta imeni V.A. Steklova
PY  - 1971
VL  - 26
IS  - 3
PB  - mathdoc
UR  - http://geodesic.mathdoc.fr/item/RM_1971_26_3_a9/
LA  - ru
ID  - RM_1971_26_3_a9
ER  -