%0 Journal Article
%A V. M. Filippov
%T The variational principle for hypoelliptic equations with constant coefficients
%J Differencialʹnye uravneniâ
%D 1986
%P 338-343
%V 22
%N 2
%I mathdoc
%U http://geodesic.mathdoc.fr/item/DE_1986_22_2_a18/
%G ru
%F DE_1986_22_2_a18