%0 Journal Article %A V. G. Limanskii %T A qualitative investigation of stable first-order differential equations with variable retardation %J Izvestiya. Mathematics %D 1970 %P 159-178 %V 4 %N 1 %I mathdoc %U http://geodesic.mathdoc.fr/item/IM2_1970_4_1_a8/ %G en %F IM2_1970_4_1_a8