@article{Stachowiak:2015,
  author  = "T. Stachowiak and W. Szumiński",
  title   = "Non-integrability of restricted double pendula",
  journal = "Physics Letters A",
  volume  = "Vol. 379",
  number  = "no. 47--48",
  pages   = "3017--3024",
  year    = "2015",
}