@article{Leoński:1999,
  author  = "W. Leoński and R. Tanaś",
  title   = "Finite energy states for periodically kicked nonlinear oscillator",
  journal = "Acta Physica Slovaca",
  volume  = "Vol. 49",
  number  = "no 4",
  pages   = "713--718",
  year    = "1999",
}