TY - JOUR AU - S. M. Nikol'skii TI - Approximation of functions by trigonometric polynomials on a JO - Doklady Akademii Nauk PY - 1991 SP - 40 EP - 44 VL - 320 IS - 1 PB - mathdoc UR - http://geodesic.mathdoc.fr/item/DAN_1991_320_1_a6/ LA - ru ID - DAN_1991_320_1_a6 ER -