TY - JOUR AU - Kh. P. Rustamov TI - Equivalence of $K$-functional and modulus of smoothness of functions on the sphere JO - Matematičeskie zametki PY - 1992 SP - 123 EP - 129 VL - 52 IS - 3 PB - mathdoc UR - http://geodesic.mathdoc.fr/item/MZM_1992_52_3_a13/ LA - ru ID - MZM_1992_52_3_a13 ER -