TY - JOUR AU - I. I. Sharapudinov TI - Approximation properties of Fej\'er- and de~la~Valle\'e-Poussin-type means for partial sums of a~special series in the system $\{\sin x\sin kx\}_{k=1}^\infty$ JO - Sbornik. Mathematics PY - 2015 SP - 600 EP - 617 VL - 206 IS - 4 PB - mathdoc UR - http://geodesic.mathdoc.fr/item/SM_2015_206_4_a5/ LA - en ID - SM_2015_206_4_a5 ER -