@book { DerWertderMarkeimInternet,
    title = "Der Wert der Marke im Internet",
    subtitle = "Am Beispiel des Handelsunternehmen Breuninger GmbH & Co",
    author = "Sabine {Wallner}",
    year = "2002",
    publisher = "Diplom.de",
    address = "Hamburg, Deutschland",
    doi = "10.3239/9783832454449",
    url = "https://m.diplom.de/document/220998"
}