%0 Journal Article %A R. M. Mints %T Limit cycles of a quadratic system of differential equations in the presence of an integral line %J Differencialʹnye uravneniâ %D 1989 %P 351-352 %V 25 %N 2 %I mathdoc %U http://geodesic.mathdoc.fr/item/DE_1989_25_2_a34/ %G ru %F DE_1989_25_2_a34