Voir la notice de l'article provenant de la source Math-Net.Ru
@article{DAN_1977_233_2_a8, author = {V. A. Rvachev}, title = {On approximation by means of the function $\operatorname{up}(x)$}, journal = {Doklady Akademii Nauk}, pages = {295--296}, publisher = {mathdoc}, volume = {233}, number = {2}, year = {1977}, language = {ru}, url = {http://geodesic.mathdoc.fr/item/DAN_1977_233_2_a8/} }
V. A. Rvachev. On approximation by means of the function $\operatorname{up}(x)$. Doklady Akademii Nauk, Tome 233 (1977) no. 2, pp. 295-296. http://geodesic.mathdoc.fr/item/DAN_1977_233_2_a8/