Voir la notice de l'article provenant de la source Math-Net.Ru
@article{TRSPY_1961_64_a5, author = {V. P. Il'in}, title = {Approximation of functions in the spaces $\widetilde W_p^{(l)}(D)$ and $W_p^{(l)}(D)$}, journal = {Informatics and Automation}, pages = {61--78}, publisher = {mathdoc}, volume = {64}, year = {1961}, language = {ru}, url = {http://geodesic.mathdoc.fr/item/TRSPY_1961_64_a5/} }
V. P. Il'in. Approximation of functions in the spaces $\widetilde W_p^{(l)}(D)$ and $W_p^{(l)}(D)$. Informatics and Automation, Trudy Matematicheskogo Instituta imeni V. A. Steklova, Tome 64 (1961), pp. 61-78. http://geodesic.mathdoc.fr/item/TRSPY_1961_64_a5/