TY  - JOUR
AU  - L. Nirenberg
AU  - F. Trèves
TI  - On local solvability of linear partial differential equations. I.~Necessary conditions
JO  - Matematika
PY  - 1971
SP  - 142
EP  - 172
VL  - 15
IS  - 3
PB  - mathdoc
UR  - http://geodesic.mathdoc.fr/item/MAT_1971_15_3_a5/
LA  - ru
ID  - MAT_1971_15_3_a5
ER  -