@article{MZM_1974_15_5_a16,
     author = {V. I. Berdyshev},
     title = {On the modulus of continuity of an operator of best approximation},
     journal = {Matemati\v{c}eskie zametki},
     pages = {797--808},
     publisher = {mathdoc},
     volume = {15},
     number = {5},
     year = {1974},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/MZM_1974_15_5_a16/}
}