@book { DerApfelbaumimSchnee,
    title = "Der Apfelbaum im Schnee",
    author = "Bernd {Saal}",
    year = "2013",
    publisher = "Schlütersche Verlagsgesellschaft mbH & Co. KG",
    address = ", Deutschland",
    url = "https://schluetersche.openpublishing.com/document/403848"
}