TY - JOUR AU - V. V. Andrievskii TI - On~approximation of functions by harmonic polynomials JO - Izvestiya. Mathematics PY - 1988 SP - 1 EP - 13 VL - 30 IS - 1 PB - mathdoc UR - http://geodesic.mathdoc.fr/item/IM2_1988_30_1_a0/ LA - en ID - IM2_1988_30_1_a0 ER -