@book { DieWerttreiberimmateriellenVermgens,
    title = "Die Werttreiber immateriellen Vermögens",
    author = "Michael {Kainrath}",
    year = "2003",
    publisher = "Diplom.de",
    address = "Hamburg, Deutschland",
    doi = "10.3239/9783832470289",
    url = "https://m.diplom.de/document/222337"
}