@book { ShoppingMallsimInternet,
    title = "Shopping Malls im Internet",
    author = "Jürgen {Fertig}",
    year = "1999",
    publisher = "Diplom.de",
    address = "Hamburg, Deutschland",
    doi = "10.3239/9783832417963",
    url = "https://m.diplom.de/document/217652"
}