%0 Journal Article %A A. V. Lutsenko %A L. V. Stadnikova %T Partial stability in the first approximation %J Differencialʹnye uravneniâ %D 1973 %P 1530-1533 %V 9 %N 8 %I mathdoc %U http://geodesic.mathdoc.fr/item/DE_1973_9_8_a19/ %G ru %F DE_1973_9_8_a19