@book { DieZukunftfunkt,
    title = "Die Zukunft funkt",
    author = "Matthias {Kirschner}",
    year = "2009",
    publisher = "Diplom.de",
    address = "Hamburg, Deutschland",
    doi = "10.3239/9783836634250",
    url = "https://m.diplom.de/document/227129"
}