@article{WesselVossMalbergetal.2000,
  author    = {Niels Wessel and Andreas Voss and Hagen Malberg and Christine Ziehmann and Henning U. Voss and Alexander Schirdewan and Udo Meyerfeldt and J{\"u}rgen Kurths},
  title     = {Nonlinear analysis of complex phenomena in cardiological data},
  year      = {2000},
}