%0 Journal Article %A L. M. Kuks %T Theorems in the qualitative theory of strongly elliptic second-order systems %J Trudy Matematicheskogo Instituta imeni V.A. Steklova %D 1962 %V 17 %N 3 %I mathdoc %U http://geodesic.mathdoc.fr/item/RM_1962_17_3_a6/ %G ru %F RM_1962_17_3_a6