%0 Journal Article %A V. Sh. Roitenberg %T On polynomial differential equations of the second order on a circle without singular points %J Vestnik Ûžno-Uralʹskogo gosudarstvennogo universiteta. Seriâ, Matematika, mehanika, fizika %D 2020 %P 33-40 %V 12 %N 4 %I mathdoc %U http://geodesic.mathdoc.fr/item/VYURM_2020_12_4_a3/ %G ru %F VYURM_2020_12_4_a3