%0 Journal Article
%A Hu, Y. K.
%A Kopotun, K. A.
%A Yu, X. M.
%T Constrained Approximation in Sobolev Spaces
%J Canadian journal of mathematics
%D 1997
%P 74-99
%V 49
%N 1
%U http://geodesic.mathdoc.fr/articles/10.4153/CJM-1997-004-2/
%R 10.4153/CJM-1997-004-2
%F 10_4153_CJM_1997_004_2