@article{DE_1965_1_4_a4,
     author = {V. P. Zakharov},
     title = {Limiting cycles of infinite multiplicity},
     journal = {Differencialʹnye uravneni\^a},
     pages = {464--466},
     publisher = {mathdoc},
     volume = {1},
     number = {4},
     year = {1965},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/DE_1965_1_4_a4/}
}