@book { Varianz,
    title = "Varianz",
    subtitle = "Studien zu einer kulturellen Verortung am Beispiel Walthers von der Vogelweide",
    author = "Tobias {Lüpges}",
    year = "2011",
    publisher = "Peter Lang Verlag",
    address = "Berlin, Germany",
    url = "https://www.peterlang.com/document/1108120"
}