@book { OnlineWerbungimInternet,
    title = "Online-Werbung im Internet",
    author = "Chrisovalantou {Tzivri}",
    year = "2002",
    publisher = "Diplom.de",
    address = "Hamburg, Deutschland",
    doi = "10.3239/9783832452469",
    url = "https://m.diplom.de/document/220194"
}