%0 Journal Article %A S. M. Nikol'skii %T Approximation of functions by trigonometric polynomials on a %J Doklady Akademii Nauk %D 1991 %P 40-44 %V 320 %N 1 %I mathdoc %U http://geodesic.mathdoc.fr/item/DAN_1991_320_1_a6/ %G ru %F DAN_1991_320_1_a6