@book { PowershoppingimInternet,
    title = "Powershopping im Internet",
    author = "Anke {Häussermann}",
    year = "2000",
    publisher = "Diplom.de",
    address = "Hamburg, Deutschland",
    doi = "10.3239/9783832427603",
    url = "https://m.diplom.de/document/218494"
}