@book { DasInternet,
    title = "Das Internet",
    subtitle = "Ein Marketing-Medium mit Zukunft?",
    author = "Marc {Reitz}",
    year = "2001",
    publisher = "Diplom.de",
    address = "Hamburg, Deutschland",
    doi = "10.3239/9783832435400",
    url = "https://m.diplom.de/document/219201"
}