%0 Journal Article %A V. E. Maiorov %T On linear widths of Sobolev classes and chains of extremal subspaces %J Sbornik. Mathematics %D 1982 %P 361-382 %V 41 %N 3 %I mathdoc %U http://geodesic.mathdoc.fr/item/SM_1982_41_3_a2/ %G en %F SM_1982_41_3_a2