@article{Guzik:2007,
  author  = "P. Guzik and J. Piskorski and T. Krauze and R. Schneider and K. Wesseling and A. Wykrętowicz and H. Wysocki",
  title   = "Correlations between the Poincare plot and conventional heart rate variability parameters assessed during paced breathing",
  journal = "The Journal of Physiological Sciences",
  volume  = "Vol. 57",
  number  = "no 1",
  pages   = "63--71",
  year    = "2007",
}