%0 Journal Article
%A N. N. Ural'tseva
%T General second-order quasi-linear equations and certain classes of systems of equations of elliptic type
%J Doklady Akademii Nauk
%D 1962
%P 778-781
%V 146
%N 4
%I mathdoc
%U http://geodesic.mathdoc.fr/item/DAN_1962_146_4_a10/
%G ru
%F DAN_1962_146_4_a10