@book { DierterschaftinHartmannvonAuesGregorius,
    title = "Die rîterschaft in Hartmann von Aue`s Gregorius",
    author = "",
    year = "2013",
    publisher = "GRIN Verlag",
    address = "München, Germany",
    doi = "10.3239/9783656411239",
    url = "https://www.hausarbeiten.de/document/213096"
}