@book { ProduktionsfaktorWissen,
    title = "Produktionsfaktor Wissen",
    author = "Christoph {Gäck}",
    year = "2000",
    publisher = "Diplom.de",
    address = "Hamburg, Deutschland",
    doi = "10.3239/9783832420628",
    url = "https://m.diplom.de/document/217854"
}