@book { DasGlckisteinSchmetterling,
    title = "Das Glück ist ein Schmetterling",
    author = "Irén {Beer-Kuhner} and Katrin {Bendrich} and Martina {Rühl} and Bernd {Saal} and Susann {Winkler}",
    year = "2017",
    publisher = "Schlütersche Verlagsgesellschaft mbH & Co. KG",
    address = ", Deutschland",
    url = "https://schluetersche.openpublishing.com/document/404047"
}