@article{Maciejewski:2004,
  author  = "A. Maciejewski and M. Przybylska and J. Weil",
  title   = "Non-integrability of the generalized spring-pendulum problem",
  journal = "Journal of Physics A : Mathematical and General",
  volume  = "Vol. 37",
  number  = "no 7",
  pages   = "2579--2597",
  year    = "2004",
}