Voir la notice de l'article provenant de la source Math-Net.Ru
@article{DE_1968_4_5_a2, author = {Ya. Kurzweil}, title = {Invariant sets of differential systems}, journal = {Differencialʹnye uravneni\^a}, pages = {785--797}, publisher = {mathdoc}, volume = {4}, number = {5}, year = {1968}, language = {ru}, url = {http://geodesic.mathdoc.fr/item/DE_1968_4_5_a2/} }
Ya. Kurzweil. Invariant sets of differential systems. Differencialʹnye uravneniâ, Tome 4 (1968) no. 5, pp. 785-797. http://geodesic.mathdoc.fr/item/DE_1968_4_5_a2/