%0 Journal Article
%A V. V. Lychagin
%T Local classification of first-order nonlinear partial differential equations
%J Doklady Akademii Nauk
%D 1973
%P 525-528
%V 210
%N 3
%I mathdoc
%U http://geodesic.mathdoc.fr/item/DAN_1973_210_3_a4/
%G ru
%F DAN_1973_210_3_a4