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@article{DE_1994_30_7_a6, author = {V. V. Filippov}, title = {Sequences of changes of variables and the {Li\'enard} equation}, journal = {Differencialʹnye uravneni\^a}, pages = {1148--1155}, publisher = {mathdoc}, volume = {30}, number = {7}, year = {1994}, language = {ru}, url = {http://geodesic.mathdoc.fr/item/DE_1994_30_7_a6/} }
V. V. Filippov. Sequences of changes of variables and the Li\'enard equation. Differencialʹnye uravneniâ, Tome 30 (1994) no. 7, pp. 1148-1155. http://geodesic.mathdoc.fr/item/DE_1994_30_7_a6/