@book { WolframvonEschenbachSineklawen,
    title = "Wolfram von Eschenbach: Sine klawen",
    author = "Jana {Beisker}",
    year = "2002",
    publisher = "GRIN Verlag",
    address = "München, Germany",
    doi = "10.3239/9783640047888",
    url = "https://www.hausarbeiten.de/document/106509"
}