@book { HilfefrHelfer,
    title = "Hilfe für Helfer",
    author = "Christine {Behrens}",
    year = "2015",
    publisher = "Schlütersche Verlagsgesellschaft mbH & Co. KG",
    address = ", Deutschland",
    url = "https://schluetersche.openpublishing.com/document/403934"
}