@book { DasPortalderZukunft,
    title = "Das Portal der Zukunft",
    author = "Andreas {Michligk}",
    year = "2001",
    publisher = "Diplom.de",
    address = "Hamburg, Deutschland",
    doi = "10.3239/9783832446215",
    url = "https://m.diplom.de/document/220233"
}