%0 Journal Article
%A E. A. Sevast'yanov
%T The degree of rational approximation of functions and their differentiability
%J Izvestiya. Mathematics 
%D 1981
%P 595-600
%V 17
%N 3
%I mathdoc
%U http://geodesic.mathdoc.fr/item/IM2_1981_17_3_a6/
%G en
%F IM2_1981_17_3_a6