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@article{DE_1974_10_4_a9, author = {I. I. Pleshkan}, title = {On the problem of isochronism for systems with discontinuous right-hand sides}, journal = {Differencialʹnye uravneni\^a}, pages = {647--658}, publisher = {mathdoc}, volume = {10}, number = {4}, year = {1974}, language = {ru}, url = {http://geodesic.mathdoc.fr/item/DE_1974_10_4_a9/} }
I. I. Pleshkan. On the problem of isochronism for systems with discontinuous right-hand sides. Differencialʹnye uravneniâ, Tome 10 (1974) no. 4, pp. 647-658. http://geodesic.mathdoc.fr/item/DE_1974_10_4_a9/