@book { StrukturendesmodernenepischenTheaters,
    title = "Strukturen des modernen epischen Theaters",
    author = "Nora {Koestler}",
    year = "1981",
    publisher = "Biblion",
    address = ", Germany",
    doi = "10.3726/b12466",
    url = "https://www.peterlang.com/document/1066935"
}