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@article{DE_2006_42_5_a0, author = {V. V. Amel'kin}, title = {Strong isochronicity of the {Lienard} system}, journal = {Differencialʹnye uravneni\^a}, pages = {579--582}, publisher = {mathdoc}, volume = {42}, number = {5}, year = {2006}, language = {ru}, url = {http://geodesic.mathdoc.fr/item/DE_2006_42_5_a0/} }
V. V. Amel'kin. Strong isochronicity of the Lienard system. Differencialʹnye uravneniâ, Tome 42 (2006) no. 5, pp. 579-582. http://geodesic.mathdoc.fr/item/DE_2006_42_5_a0/