@book { Geflltgerahmtschraffiert,
    title = "Gefüllt, gerahmt, schraffiert",
    author = "Rolf {Hichert} and Jürgen {Faisst}",
    year = "2019",
    publisher = "Vahlen",
    address = "München, Deutschland",
    url = "https://vahlen.openpublishing.com/document/1221336"
}