%0 Journal Article %A A. V. Pokrovskii %T Global criteria for the existence of self-oscillatory regimes %J Doklady Akademii Nauk %D 1989 %P 1057-1060 %V 308 %N 5 %I mathdoc %U http://geodesic.mathdoc.fr/item/DAN_1989_308_5_a7/ %G ru %F DAN_1989_308_5_a7