@article{MZM_2006_80_1_a1,
     author = {S. B. Vakarchuk},
     title = {Jackson-Type {Inequalities} and {Widths} of {Function} {Classes} in~$L_2$},
     journal = {Matemati\v{c}eskie zametki},
     pages = {11--19},
     publisher = {mathdoc},
     volume = {80},
     number = {1},
     year = {2006},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/MZM_2006_80_1_a1/}
}