@book { DieSpectatorsinSpanien,
    title = "Die «Spectators» in Spanien",
    author = "Klaus-Dieter {Ertler} and Jessica {Köhldorfer}",
    year = "2021",
    publisher = "Peter Lang Verlag",
    address = "Berlin, Germany",
    url = "https://www.peterlang.com/document/1135375"
}