TY - JOUR AU - M. I. Ganzburg TI - A~direct and inverse theorem on approximation by polynomials on the $m$- dimensional ball JO - Informatics and Automation PY - 1987 SP - 91 EP - 92 VL - 180 PB - mathdoc UR - http://geodesic.mathdoc.fr/item/TRSPY_1987_180_a48/ LA - ru ID - TRSPY_1987_180_a48 ER -