%0 Journal Article
%A Yu. E. Karpeshina
%T Analytic perturbation theory for a~periodic potential
%J Izvestiya. Mathematics 
%D 1990
%P 43-64
%V 34
%N 1
%I mathdoc
%U http://geodesic.mathdoc.fr/item/IM2_1990_34_1_a2/
%G en
%F IM2_1990_34_1_a2