@article{DAN_1957_114_1_a6,
     author = {B. M. Peretyagin},
     title = {On the number of limit cycles of equation $\frac{dy}{dx}=\frac{cx+dy+P(x,y)}{ax+by+Q(x,y)}$ where $P(x,y)$ and $Q(x,y)$ are homogeneous polynomials of degree~$n$},
     journal = {Doklady Akademii Nauk},
     pages = {29--32},
     publisher = {mathdoc},
     volume = {114},
     number = {1},
     year = {1957},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/DAN_1957_114_1_a6/}
}