%0 Journal Article
%A V. M. Filippov
%A V. M. Savchin
%A S. A. Budochkina
%T Bi-variationality, symmetries and approximate solutions
%J Contemporary Mathematics. Fundamental Directions
%D 2021
%P 596-608
%V 67
%N 3
%I mathdoc
%U http://geodesic.mathdoc.fr/item/CMFD_2021_67_3_a12/
%G ru
%F CMFD_2021_67_3_a12