@book { AlfonsPetzoldStefanZweig,
    title = "Alfons Petzold - Stefan Zweig",
    subtitle = "Briefwechsel",
    author = "Alfons {Petzold} and Stefan {Zweig}",
    year = "1998",
    publisher = "Peter Lang Verlag",
    address = "New York, United States of America",
    url = "https://www.peterlang.com/document/1087513"
}