@article{DAN_1964_154_2_a8,
     author = {A. F. Timan},
     title = {A problem in approximation theory related to the superposition of functions},
     journal = {Doklady Akademii Nauk},
     pages = {274--275},
     publisher = {mathdoc},
     volume = {154},
     number = {2},
     year = {1964},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/DAN_1964_154_2_a8/}
}