@book { TrkenangstundFestungsbau,
    title = "Türkenangst und Festungsbau",
    author = "Harald {Heppner} and Zsuzsa {Barbarics-Hermanik}",
    year = "2021",
    publisher = "Peter Lang Verlag",
    address = "Berlin, Germany",
    url = "https://www.peterlang.com/document/1107200"
}