%0 Journal Article
%A V. F. Lazutkin
%T The width of the instability zone around separatrices of a
%J Doklady Akademii Nauk
%D 1990
%P 268-272
%V 313
%N 2
%I mathdoc
%U http://geodesic.mathdoc.fr/item/DAN_1990_313_2_a1/
%G ru
%F DAN_1990_313_2_a1