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@article{DE_1979_15_6_a4, author = {S. Yu. Pilyugin}, title = {Periodic trajectories and the structure of phase diagrams}, journal = {Differencialʹnye uravneni\^a}, pages = {1000--1006}, publisher = {mathdoc}, volume = {15}, number = {6}, year = {1979}, language = {ru}, url = {http://geodesic.mathdoc.fr/item/DE_1979_15_6_a4/} }
S. Yu. Pilyugin. Periodic trajectories and the structure of phase diagrams. Differencialʹnye uravneniâ, Tome 15 (1979) no. 6, pp. 1000-1006. http://geodesic.mathdoc.fr/item/DE_1979_15_6_a4/