%0 Journal Article %A V. P. Il'in %T Approximation of functions in the spaces $\widetilde W_p^{(l)}(D)$ and $W_p^{(l)}(D)$ %J Informatics and Automation %D 1961 %P 61-78 %V 64 %I mathdoc %U http://geodesic.mathdoc.fr/item/TRSPY_1961_64_a5/ %G ru %F TRSPY_1961_64_a5