@article{DAN_1978_242_2_a4,
     author = {N. P. Korneichuk},
     title = {Sharp inequalities for best approximation by splines},
     journal = {Doklady Akademii Nauk},
     pages = {280--283},
     publisher = {mathdoc},
     volume = {242},
     number = {2},
     year = {1978},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/DAN_1978_242_2_a4/}
}