@book { DieSpectatorsinSpanien,
    title = "Die «Spectators» in Spanien",
    author = "Klaus-Dieter {Ertler} and Elisabeth {Hobisch} and Andrea Maria {Humpl}",
    year = "2014",
    publisher = "Peter Lang Verlag",
    address = "Berlin, Germany",
    doi = "10.3726/978-3-653-04080-7",
    url = "https://www.peterlang.com/document/1047996"
}