@article{Stulpe2009,
  author    = {Stulpe, Werner},
  title     = {Unitary Operator},
  series = {Compendium of Quantum Physics : concepts, experiments, history and philosophy / Daniel Greenberger ... ed.},
  journal   = {Compendium of Quantum Physics : concepts, experiments, history and philosophy / Daniel Greenberger ... ed.},
  publisher = {Springer},
  address   = {Berlin},
  isbn      = {978-3-540-70622-9},
  pages     = {807 -- 809},
  year      = {2009},
  language  = {en}
}
@article{KotliarVilserSchmidtTrucksaessetal.2009,
  author    = {Kotliar, Konstantin and Vilser, W. and Schmidt-Trucks{\"a}ss, A. and Halle, M. and Lanzl, I. M.},
  title     = {Zeitliche Schwingungen retinaler Gef{\"a}ßdurchmesser bei Gesunden unterschiedlichen Alters : Kreuz- und Autokorrelation f{\"u}r dynamische Gef{\"a}ßanalyse},
  series = {Der Ophthalmologe},
  volume    = {106},
  journal   = {Der Ophthalmologe},
  number    = {7},
  publisher = {-},
  isbn      = {1433-0423},
  pages     = {609 -- 618},
  year      = {2009},
  language  = {de}
}