@article{Piskorski:2007,
  author  = "J. Piskorski and P. Guzik",
  title   = "Geometry of the Poincaré plot of RR intervals and its asymmetry in healthy adults",
  journal = "Physiological Measurement",
  volume  = "Vol. 28",
  pages   = "287--300",
  year    = "2007",
}