@article{Żurek:2012,
  author  = "S. Żurek and P. Castiglioni and M. Kośmider and G. Parati and P. Guzik and J. Piskorski",
  title   = "A characteristic ridge-ledge in entropy surfaces of cardiovascular time series estimated by the norm component matrix algorithm",
  journal = "Computing in Cardiology",
  volume  = "Vol. 39",
  pages   = "281--284",
  year    = "2012",
}