%0 Journal Article %A G. Solntzev %T On stability according to Lyapunov of the equilibrium positions of a system of two differential equations in the case of discontinuous right hand sides %J Uchenye Zapiski Moskovskogo Gosudarstvennogo Universiteta %D 1951 %P 144-180 %V 148 %N 148 %I mathdoc %U http://geodesic.mathdoc.fr/item/UZMU_1951_148_148_a10/ %G ru %F UZMU_1951_148_148_a10