@article{Piskorski:2011,
  author  = "J. Piskorski and P. Guzik",
  title   = "Asymmetric properties of long-term and total heart rate variability",
  journal = "Medical & Biological Engineering & Computing",
  volume  = "Vol. 49",
  number  = "no 11",
  pages   = "1289--1297",
  year    = "2011",
}