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@article{DE_1977_13_5_a9, author = {S. Yu. Pilyugin}, title = {Cycles in phase portraits of {Morse--Smale} systems}, journal = {Differencialʹnye uravneni\^a}, pages = {874--882}, publisher = {mathdoc}, volume = {13}, number = {5}, year = {1977}, language = {ru}, url = {http://geodesic.mathdoc.fr/item/DE_1977_13_5_a9/} }
S. Yu. Pilyugin. Cycles in phase portraits of Morse--Smale systems. Differencialʹnye uravneniâ, Tome 13 (1977) no. 5, pp. 874-882. http://geodesic.mathdoc.fr/item/DE_1977_13_5_a9/