%0 Journal Article
%A A. I. Korotkii
%T On the extension of extremal problems that are connected with controllable elliptic systems
%J Differencialʹnye uravneniâ
%D 1989
%P 1518-1522
%V 25
%N 9
%I mathdoc
%U http://geodesic.mathdoc.fr/item/DE_1989_25_9_a6/
%G ru
%F DE_1989_25_9_a6