%0 Journal Article %A V. B. Pilyugina %T Investigation of a system with a triple zero characteristic root %J Differencialʹnye uravneniâ %D 1980 %P 1520-1522 %V 16 %N 8 %I mathdoc %U http://geodesic.mathdoc.fr/item/DE_1980_16_8_a20/ %G ru %F DE_1980_16_8_a20