Voir la notice de l'article provenant de la source Math-Net.Ru
@article{DE_1970_6_10_a17, author = {L. I. Zhilevich}, title = {The uniqueness conditions for the limit cycle}, journal = {Differencialʹnye uravneni\^a}, pages = {1888--1891}, publisher = {mathdoc}, volume = {6}, number = {10}, year = {1970}, language = {ru}, url = {http://geodesic.mathdoc.fr/item/DE_1970_6_10_a17/} }
L. I. Zhilevich. The uniqueness conditions for the limit cycle. Differencialʹnye uravneniâ, Tome 6 (1970) no. 10, pp. 1888-1891. http://geodesic.mathdoc.fr/item/DE_1970_6_10_a17/