%0 Journal Article
%A M. I. Vishik
%A L. A. Lyusternik
%T The solution of some perturbation problems for matrices and selfadjoint or non-selfadjoint differential equations.~I
%J Trudy Matematicheskogo Instituta imeni V.A. Steklova
%D 1960
%P 1-73
%V 15
%N 3
%I mathdoc
%U http://geodesic.mathdoc.fr/item/RM_1960_15_3_a0/
%G en
%F RM_1960_15_3_a0