%0 Journal Article
%A N. A. Izobov
%T The transfer of the Lyapunov integral criterion to two-dimensional periodic systems of second order
%J Matematičeskie zametki
%D 1977
%P 817-828
%V 21
%N 6
%I mathdoc
%U http://geodesic.mathdoc.fr/item/MZM_1977_21_6_a8/
%G ru
%F MZM_1977_21_6_a8