@article{DE_1969_5_10_a8,
     author = {I. K. Lipenkov},
     title = {The type $D$ curves of the differential equation $(x+\xi)(x+\eta)yy'=P_3(x,y)$ which arise from a second order closed curve},
     journal = {Differencialʹnye uravneni\^a},
     pages = {1830--1835},
     publisher = {mathdoc},
     volume = {5},
     number = {10},
     year = {1969},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/DE_1969_5_10_a8/}
}