%0 Journal Article %A B. M. Arkhipov %A A. Ya. Khokhryakov %T Strictly positive periodic solutions of a nonlinear ordinary differential equation %J Differencialʹnye uravneniâ %D 1978 %P 798-806 %V 14 %N 5 %I mathdoc %U http://geodesic.mathdoc.fr/item/DE_1978_14_5_a1/ %G ru %F DE_1978_14_5_a1