%0 Journal Article %A R. M. Bulatovic %T Notes on the instability of equilibrium in nonholonomic systems %J Vestnik Moskovskogo universiteta. Matematika, mehanika %D 1989 %P 57-60 %N 4 %U http://geodesic.mathdoc.fr/item/VMUMM_1989_4_a13/ %G ru %F VMUMM_1989_4_a13