%0 Journal Article
%A B. T. Polyak
%T Semicontinuity of integral functionals and existence theorems on extremal problems
%J Sbornik. Mathematics
%D 1969
%P 59-77
%V 7
%N 1
%U http://geodesic.mathdoc.fr/item/SM_1969_7_1_a2/
%G en
%F SM_1969_7_1_a2