%0 Journal Article
%A V. L. Berdichevsky
%T A variational principle
%J Doklady Akademii Nauk
%D 1974
%P 1329-1332
%V 215
%N 6
%I mathdoc
%U http://geodesic.mathdoc.fr/item/DAN_1974_215_6_a12/
%G ru
%F DAN_1974_215_6_a12