@article{DE_1998_34_12_a0,
     author = {{\CYRCH}. {\CYRD}{\cyro}{\cyrl}{\cyri}{\cyrch}{\cyra}{\cyrn}{\cyri}{\cyrn} and V. G. Romanovsky and M. Stefanovich},
     title = {Center conditions and cyclicity of certain cubic vector fields},
     journal = {Differencialʹnye uravneni\^a},
     pages = {1587--1595},
     publisher = {mathdoc},
     volume = {34},
     number = {12},
     year = {1998},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/DE_1998_34_12_a0/}
}