%0 Journal Article
%A V. I. Blagodatskikh
%T Letter to the editors: ``A sufficient optimality condition'' (Differencial'nye Uravnenija \textbf{9} (1973), 416--422)
%J Differencialʹnye uravneniâ
%D 1973
%P 2112
%V 9
%N 11
%I mathdoc
%U http://geodesic.mathdoc.fr/item/DE_1973_9_11_a28/
%G ru
%F DE_1973_9_11_a28