%0 Journal Article %A E. G. D'yakonov %T On Spectral Problems in Energy Spaces on Composite Manifolds with Singular Geometry of the Blocks:~I %J Differencialʹnye uravneniâ %D 2004 %P 874-886 %V 40 %N 7 %I mathdoc %U http://geodesic.mathdoc.fr/item/DE_2004_40_7_a1/ %G ru %F DE_2004_40_7_a1