%0 Journal Article
%A V. G. Boltyanskii
%T Necessary conditions for the extremum of a function
%J Differencialʹnye uravneniâ
%D 1972
%P 1553-1559
%V 8
%N 9
%I mathdoc
%U http://geodesic.mathdoc.fr/item/DE_1972_8_9_a2/
%G ru
%F DE_1972_8_9_a2