@article{DAN_1961_139_1_a0,
     author = {N. N. Brushlinskaya},
     title = {Qualitative integration of a system of $n$~differential equations in a region containing a singular point and a limit cycle},
     journal = {Doklady Akademii Nauk},
     pages = {9--12},
     publisher = {mathdoc},
     volume = {139},
     number = {1},
     year = {1961},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/DAN_1961_139_1_a0/}
}