@article{DAN_1958_121_3_a7,
     author = {S. A. Telyakovskii},
     title = {Approximation of differentiable functions by de la {Vall\'ee} {Poussin's} sums},
     journal = {Doklady Akademii Nauk},
     pages = {426--429},
     publisher = {mathdoc},
     volume = {121},
     number = {3},
     year = {1958},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/DAN_1958_121_3_a7/}
}