%0 Journal Article
%A A. M. Samoilenko
%T Preservation of an invariant torus under perturbation
%J Izvestiya. Mathematics 
%D 1970
%P 1225-1249
%V 4
%N 6
%I mathdoc
%U http://geodesic.mathdoc.fr/item/IM2_1970_4_6_a3/
%G en
%F IM2_1970_4_6_a3