%0 Journal Article %A V. P. Prokop'ev %T On the stability of systems with aftereffect in the critical case of two zero roots %J Differencialʹnye uravneniâ %D 1968 %P 2027-2033 %V 4 %N 11 %I mathdoc %U http://geodesic.mathdoc.fr/item/DE_1968_4_11_a11/ %G ru %F DE_1968_4_11_a11