@book { DasgemeinschaftlicheTestament,
    title = "Das gemeinschaftliche Testament",
    author = "Alfons {Rau}",
    year = "2008",
    publisher = "Diplom.de",
    address = "Hamburg, Deutschland",
    doi = "10.3239/9783836609357",
    url = "https://m.diplom.de/document/229091"
}