@book { DieBildungamHofKarlsdesGroen,
    title = "Die Bildung am Hof Karls des Großen",
    author = "Toralf {Schrader}",
    year = "2008",
    publisher = "GRIN Verlag",
    address = "München, Germany",
    doi = "10.3239/9783640233465",
    url = "https://www.hausarbeiten.de/document/119810"
}