@book { ChristiansGeheimnis,
    title = "Christians Geheimnis",
    author = "Brigitte {Kaindl} and Brenda {Leb}",
    year = "2021",
    publisher = "via tolino media",
    address = "München, Deutschland",
    url = "https://tolino.openpublishing.com/document/1007964"
}