@article{Maciejewski:2001,
  author  = "A. Maciejewski and M. Szydłowski",
  title   = "Integrability and non-integrability of planar Hamiltonian systems of cosmological origin",
  journal = "Journal of Nonlinear Mathematical Physics",
  volume  = "Vol. 8",
  number  = "Suppl.",
  pages   = "200--206",
  year    = "2001",
}