%0 Journal Article %A S. A. Telyakovskii %T Estimating the integral of the derivative of the sum of a trigonometric series with quasi-convex coefficients %J Sbornik. Mathematics %D 1995 %P 1659-1669 %V 186 %N 11 %U http://geodesic.mathdoc.fr/item/SM_1995_186_11_a4/ %G en %F SM_1995_186_11_a4