%0 Journal Article
%A A. Langenbach
%T On the application of the variation principle to some nonlinear differential equations
%J Doklady Akademii Nauk
%D 1958
%P 214-217
%V 121
%N 2
%I mathdoc
%U http://geodesic.mathdoc.fr/item/DAN_1958_121_2_a4/
%G ru
%F DAN_1958_121_2_a4