@article{Maciejewski:1998,
  author  = "A. Maciejewski and S. Rybicki",
  title   = "Global bifurcations of periodic solutions of Henon-Heiles system via degree for S-equivariant orthogonal maps",
  journal = "Reviews in Mathematical Physics",
  volume  = "Vol. 10",
  number  = "no 8",
  pages   = "1125--1146",
  year    = "1998",
}