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@article{DE_1969_5_7_a0, author = {A. P. Vorob'ev}, title = {The cycles of a certain first order equation}, journal = {Differencialʹnye uravneni\^a}, pages = {1159--1166}, publisher = {mathdoc}, volume = {5}, number = {7}, year = {1969}, language = {ru}, url = {http://geodesic.mathdoc.fr/item/DE_1969_5_7_a0/} }
A. P. Vorob'ev. The cycles of a certain first order equation. Differencialʹnye uravneniâ, Tome 5 (1969) no. 7, pp. 1159-1166. http://geodesic.mathdoc.fr/item/DE_1969_5_7_a0/