%0 Journal Article %A A. I. Zhivkov %T Geometry of invariant manifolds of a gyroscope in the field of a quadratic potential %J Izvestiya. Mathematics %D 1991 %P 227-242 %V 37 %N 1 %I mathdoc %U http://geodesic.mathdoc.fr/item/IM2_1991_37_1_a9/ %G en %F IM2_1991_37_1_a9