%0 Journal Article %A Yu. D. Golovatyj %A S. A. Nazarov %A O. A. Oleinik %T Asymptotic expansions of eigenvalues and eigenfunctions in problems on oscillations of a~medium with concentrated perturbations %J Trudy Matematicheskogo Instituta imeni V.A. Steklova %D 1990 %P 42-60 %V 192 %I mathdoc %U http://geodesic.mathdoc.fr/item/TM_1990_192_a4/ %G ru %F TM_1990_192_a4