%0 Journal Article
%A Yu. P. Krivenkov
%T Sufficient optimality conditions for problems with second order differential equations of elliptic type in the presence of phase constraints
%J Differencialʹnye uravneniâ
%D 1975
%P 85-99
%V 11
%N 1
%I mathdoc
%U http://geodesic.mathdoc.fr/item/DE_1975_11_1_a10/
%G ru
%F DE_1975_11_1_a10