Voir la notice de l'article provenant de la source Math-Net.Ru
@article{DE_1966_2_3_a4, author = {A. I. Yablonskii}, title = {On limit cycles of a certain differential equation}, journal = {Differencialʹnye uravneni\^a}, pages = {335--344}, publisher = {mathdoc}, volume = {2}, number = {3}, year = {1966}, language = {ru}, url = {http://geodesic.mathdoc.fr/item/DE_1966_2_3_a4/} }
A. I. Yablonskii. On limit cycles of a certain differential equation. Differencialʹnye uravneniâ, Tome 2 (1966) no. 3, pp. 335-344. http://geodesic.mathdoc.fr/item/DE_1966_2_3_a4/