@book { PrfungundBeratung,
    title = "Prüfung und Beratung",
    author = "Nils {Bolender}",
    year = "2005",
    publisher = "Diplom.de",
    address = "Hamburg, Germany",
    doi = "10.3239/9783832445294",
    url = "https://m.diplom.de/document/220129"
}