@article{DE_1999_35_6_a2,
     author = {M. Gillenberg and A. V. Osipov},
     title = {Limit cycles in the two-dimensional {May} problem},
     journal = {Differencialʹnye uravneni\^a},
     pages = {733--737},
     publisher = {mathdoc},
     volume = {35},
     number = {6},
     year = {1999},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/DE_1999_35_6_a2/}
}