@book { Schutzengelgebenniemalsauf,
    title = "Schutzengel geben niemals auf",
    author = "Peter {Jäger}",
    year = "2017",
    publisher = "Bedey Media GmbH",
    address = "Hamburg, Deutschland",
    url = "https://kaderaverlag.openpublishing.com/document/380958"
}