@book { BetrieblicheAltersversorgung,
    title = "Betriebliche Altersversorgung",
    author = "Rainer {Wilz}",
    year = "2005",
    publisher = "Diplom.de",
    address = "Hamburg, Deutschland",
    doi = "10.3239/9783832440657",
    url = "https://m.diplom.de/document/219694"
}