%0 Journal Article %A D. G. Rakhimov %T Reductional method in perturbation theory of generalized spectral E.~Schmidt problem %J Contemporary Mathematics. Fundamental Directions %D 2019 %P 72-82 %V 65 %N 1 %I mathdoc %U http://geodesic.mathdoc.fr/item/CMFD_2019_65_1_a6/ %G ru %F CMFD_2019_65_1_a6