%0 Journal Article %A L. Nirenberg %A F. Trèves %T On local solvability of linear partial differential equations. II.~Sufficient conditions %J Matematika %D 1971 %P 68-110 %V 15 %N 4 %I mathdoc %U http://geodesic.mathdoc.fr/item/MAT_1971_15_4_a2/ %G ru %F MAT_1971_15_4_a2