@article{DE_1999_35_1_a0,
     author = {V. V. Amel'kin and A. B. Levin},
     title = {A criterion for the stability of multiple limit cycles},
     journal = {Differencialʹnye uravneni\^a},
     pages = {3--7},
     publisher = {mathdoc},
     volume = {35},
     number = {1},
     year = {1999},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/DE_1999_35_1_a0/}
}