@article{DE_1969_5_11_a7,
     author = {M. V. Dolov},
     title = {Limit {Cycles} and analytic integrals},
     journal = {Differencialʹnye uravneni\^a},
     pages = {2026--2033},
     publisher = {mathdoc},
     volume = {5},
     number = {11},
     year = {1969},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/DE_1969_5_11_a7/}
}