%0 Journal Article %A V. V. Strygin %T “Exchange of stabilities” and bifurcation of small auto-oscillations of systems of differential equations with %J Doklady Akademii Nauk %D 1971 %P 33-35 %V 199 %N 1 %U http://geodesic.mathdoc.fr/item/DAN_1971_199_1_a7/ %G ru %F DAN_1971_199_1_a7