%0 Journal Article %A Yu. V. Usachev %T Bifurcation of invariant tori in a neighborhood of an equilibrium of a system of ordinary differential equations %J Differencialʹnye uravneniâ %D 2000 %P 569-571 %V 36 %N 4 %I mathdoc %U http://geodesic.mathdoc.fr/item/DE_2000_36_4_a22/ %G ru %F DE_2000_36_4_a22