%0 Journal Article
%A A. P. Sadovskii
%T Cubic Systems of Nonlinear Oscillations with Seven Limit Cycles
%J Differencialʹnye uravneniâ
%D 2003
%P 472-481
%V 39
%N 4
%I mathdoc
%U http://geodesic.mathdoc.fr/item/DE_2003_39_4_a4/
%G ru
%F DE_2003_39_4_a4