@book { BerufsbilddesControllers,
    title = "Berufsbild des Controllers",
    author = "Eugen {Fenzlein}",
    year = "2008",
    publisher = "Diplom.de",
    address = "Hamburg, Deutschland",
    doi = "10.3239/9783836617666",
    url = "https://m.diplom.de/document/226055"
}