%0 Journal Article
%A V. P. Fedotov
%T The extremum principle for a system of equations
%J Differencialʹnye uravneniâ
%D 1980
%P 679-683
%V 16
%N 4
%I mathdoc
%U http://geodesic.mathdoc.fr/item/DE_1980_16_4_a9/
%G ru
%F DE_1980_16_4_a9