Voir la notice de l'article provenant de la source Math-Net.Ru
@article{FAA_1978_12_1_a1, author = {B. E. Klots}, title = {Best linear and nonlinear approximations for smooth functions}, journal = {Funkcionalʹnyj analiz i ego prilo\v{z}eni\^a}, pages = {15--24}, publisher = {mathdoc}, volume = {12}, number = {1}, year = {1978}, language = {ru}, url = {http://geodesic.mathdoc.fr/item/FAA_1978_12_1_a1/} }
B. E. Klots. Best linear and nonlinear approximations for smooth functions. Funkcionalʹnyj analiz i ego priloženiâ, Tome 12 (1978) no. 1, pp. 15-24. http://geodesic.mathdoc.fr/item/FAA_1978_12_1_a1/