@book{BaumannBeenkenSandk{\"u}hler2013,
  author    = {Baumann, Frank and Beenken, Matthias and Sandk{\"u}hler, Hans-Ludger},
  title     = {Handbuch Maklermanagement},
  publisher = {Haufe},
  address   = {Freiburg},
  isbn      = {978-3-648-02408-9},
  pages     = {352},
  year      = {2013},
  language  = {de}
}
@book{Beenken2013,
  author    = {Beenken, Matthias},
  title     = {Der Versicherungsvermittler als Unternehmer},
  publisher = {Verlag Versicherungswirtschaft},
  address   = {Karlsruhe},
  isbn      = {978-3-89952-458-1},
  pages     = {XV, 229},
  year      = {2013},
  language  = {de}
}
@book{Beenken2013,
  author    = {Beenken, Matthias},
  title     = {Vertriebsmanagement},
  publisher = {Verlag Versicherungswirtschaft},
  address   = {Karlsruhe},
  isbn      = {978-3-89952-732-2},
  pages     = {XIX, 240},
  year      = {2013},
  language  = {de}
}