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@article{DE_1984_20_11_a3, author = {N. S. Leonovich}, title = {Classes of third-order systems without moving critical points}, journal = {Differencialʹnye uravneni\^a}, pages = {1869--1877}, publisher = {mathdoc}, volume = {20}, number = {11}, year = {1984}, language = {ru}, url = {http://geodesic.mathdoc.fr/item/DE_1984_20_11_a3/} }
N. S. Leonovich. Classes of third-order systems without moving critical points. Differencialʹnye uravneniâ, Tome 20 (1984) no. 11, pp. 1869-1877. http://geodesic.mathdoc.fr/item/DE_1984_20_11_a3/