%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 Trudy Matematicheskogo Instituta imeni V.A. Steklova
%D 1961
%P 61-78
%V 64
%I mathdoc
%U http://geodesic.mathdoc.fr/item/TM_1961_64_a5/
%G ru
%F TM_1961_64_a5