@book { HildegardvonBingen,
    title = "Hildegard von Bingen",
    author = "Katharina {Krabbe}",
    year = "2009",
    publisher = "GRIN Verlag",
    address = "München, Germany",
    doi = "10.3239/9783640484416",
    url = "https://www.hausarbeiten.de/document/140315"
}