Dovnar S I

Publications in Math-Net.Ru

1. Curves of Separatrix Cycles of a Quadratic System. The Case of Three Antisaddles and One Saddle
   
   Differ. Uravn., 38:3 (2002),  313–318
2. The curve of separatrix cycles of an autonomous quadratic system in the plane. The case of two anti-saddles
   
   Differ. Uravn., 32:1 (1996),  15–21