@article{Nakagawa:2005,
  author  = "K. Nakagawa and A. Maciejewski and M. Przybylska",
  title   = "New integrable Hamiltonian system with first integral quartic in momenta",
  journal = "Physics Letters A",
  volume  = "Vol. 343",
  pages   = "171--173",
  year    = "2005",
}