@book { Berufsunfhigkeit,
    title = "Berufsunfähigkeit",
    author = "Katrin {Landmann}",
    year = "2005",
    publisher = "Diplom.de",
    address = "Hamburg, Deutschland",
    doi = "10.3239/9783832491154",
    url = "https://m.diplom.de/document/224273"
}