%0 Journal Article
%A N. P. Korneichuk
%T Extreme values of functionals and best approximation on classes of periodic functions
%J Izvestiya. Mathematics 
%D 1971
%P 97-129
%V 5
%N 1
%I mathdoc
%U http://geodesic.mathdoc.fr/item/IM2_1971_5_1_a7/
%G en
%F IM2_1971_5_1_a7