%0 Journal Article %A S. I. Pokhozhaev %T On subordinate operators of nonlinear equations %J Doklady Akademii Nauk %D 1981 %P 282-286 %V 257 %N 2 %I mathdoc %U http://geodesic.mathdoc.fr/item/DAN_1981_257_2_a5/ %G ru %F DAN_1981_257_2_a5