TY - JOUR AU - L. Nirenberg AU - F. Trèves TI - On local solvability of linear partial differential equations. II.~Sufficient conditions JO - Matematika PY - 1971 SP - 68 EP - 110 VL - 15 IS - 4 PB - mathdoc UR - http://geodesic.mathdoc.fr/item/MAT_1971_15_4_a2/ LA - ru ID - MAT_1971_15_4_a2 ER -