%0 Journal Article %A A. P. Begun %T On the number of periodic solutions generated by a singular periodic solution %J Differencialʹnye uravneniâ %D 1999 %P 1132-1134 %V 35 %N 8 %I mathdoc %U http://geodesic.mathdoc.fr/item/DE_1999_35_8_a17/ %G ru %F DE_1999_35_8_a17