@article{UFA_2021_13_1_a4,
     author = {M. R. Langarshoev and S. S. Khorazmshoev},
     title = {Sharp inequalities of {Jackson-Stechkin} type  and   widths of classes of functions in $L_{2}$},
     journal = {Ufa mathematical journal},
     pages = {56--67},
     publisher = {mathdoc},
     volume = {13},
     number = {1},
     year = {2021},
     language = {en},
     url = {http://geodesic.mathdoc.fr/item/UFA_2021_13_1_a4/}
}