@TechReport{TR-2010-2,
  author = {Gasterst{\"a}dt, Stefan and Schnor, Bettina},
  title = {{What VoIP-CDR can tell us (not)?}},
  institution = {{Potsdam University, Germany}},
  year = 2010,
  month = may,
  type = "Technical Report",
  number = "ISSN 0946-7580, TR-2010-2",
}