@book { InternetGebrauchtwagenbrseundCallCenter,
    title = "Internet-Gebrauchtwagenbörse und Call-Center",
    author = "Marco {Zuzak}",
    year = "2000",
    publisher = "Diplom.de",
    address = "Hamburg, Deutschland",
    doi = "10.3239/9783832424404",
    url = "https://m.diplom.de/document/218238"
}