@article{Abramowicz:2003,
  author  = "M. Abramowicz and W. Klužniak",
  title   = "Epicyclic orbital oscillations in Newton's and Einstein's dynamics",
  journal = "General Relativity and Gravitation",
  volume  = "Vol. 35",
  number  = "no 1",
  pages   = "69--77",
  year    = "2003",
}