%0 Journal Article
%A A. G. Eliseev
%T Singular perturbation theory for systems of differential equations in the case of multiple spectrum of the limit operator.~I,~II
%J Izvestiya. Mathematics 
%D 1985
%P 315-357
%V 25
%N 2
%I mathdoc
%U http://geodesic.mathdoc.fr/item/IM2_1985_25_2_a3/
%G en
%F IM2_1985_25_2_a3