@book { PensionszusagenanGmbHGeschftsfhrer,
    title = "Pensionszusagen an GmbH-Geschäftsführer",
    author = "Tina {Timpl}",
    year = "2009",
    publisher = "Diplom.de",
    address = "Hamburg, Deutschland",
    doi = "10.3239/9783836628389",
    url = "https://m.diplom.de/document/226715"
}