@article{DAN_1973_212_1_a2,
     author = {V. V. Zhuk and G. I. Natanson},
     title = {Properties of functions, and growth of the derivatives of the approximating polynomials},
     journal = {Doklady Akademii Nauk},
     pages = {19--22},
     publisher = {mathdoc},
     volume = {212},
     number = {1},
     year = {1973},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/DAN_1973_212_1_a2/}
}