@book { DieSymbolikinderspterenLyrikBrechts,
    title = "Die Symbolik in der späteren Lyrik Brechts",
    author = "Nosratollah {Rastegar}",
    year = "1979",
    publisher = "Peter Lang Verlag",
    address = "Berlin, Germany",
    url = "https://www.peterlang.com/document/1070392"
}