%0 Journal Article %A V. P. Nozdracheva %T Estimates for the periods of cycles generated by a structurally unstable separatrix loop %J Differencialʹnye uravneniâ %D 1992 %P 612-618 %V 28 %N 4 %I mathdoc %U http://geodesic.mathdoc.fr/item/DE_1992_28_4_a7/ %G ru %F DE_1992_28_4_a7