@article{DE_1968_4_6_a20,
     author = {P. S. Belevets},
     title = {A certain class of dynamical systems with two closed algebraic trajectories},
     journal = {Differencialʹnye uravneni\^a},
     pages = {1150--1153},
     publisher = {mathdoc},
     volume = {4},
     number = {6},
     year = {1968},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/DE_1968_4_6_a20/}
}