@book { AufeineTasseKaffeemitGott,
    title = "Auf eine Tasse Kaffee mit Gott",
    author = "Martin {Dubberke}",
    year = "2020",
    publisher = "via tolino media",
    address = "München, Deutschland",
    url = "https://tolino.openpublishing.com/document/1000764"
}