%0 Journal Article %A N. A. Ilyasov %T Some supplements to S. B. Stechkin's inequalities in direct and inverse theorems on the approximation of continuous periodic functions %J Trudy Instituta matematiki i mehaniki %D 2020 %P 155-181 %V 26 %N 4 %I mathdoc %U http://geodesic.mathdoc.fr/item/TIMM_2020_26_4_a10/ %G ru %F TIMM_2020_26_4_a10