@article{Guzik:2006,
  author  = "P. Guzik and J. Piskorski and T. Krauze and A. Wykrętowicz and H. Wysocki",
  title   = "Heart rate asymmetry by Poincare plots of RR intervals",
  journal = "Biomedizinische Technik",
  volume  = "Vol. 51",
  number  = "4",
  pages   = "272--275",
  year    = "2006",
}