@book { DerButler02DasRungholtRtsel,
    title = "Der Butler 02: Das Rungholt-Rätsel",
    author = "J. J. {Preyer}",
    year = "2020",
    publisher = "Blitz-Verlag",
    address = ", Deutschland",
    url = "https://tolino.openpublishing.com/document/1039059"
}