@book { DerheilendeKernderGrapefruitWirkungundAnwendung,
    title = "Der heilende Kern der Grapefruit - Wirkung und Anwendung",
    author = "Ingrid {Pfendtner}",
    year = "2015",
    publisher = "Open Publishing",
    address = "München, Deutschland",
    url = "https://books.openpublishing.com/document/288854"
}