@book { FortressEuropeoraEuropeofFortresses,
    title = "Fortress Europe or a Europe of Fortresses?",
    author = "Harlan {Koff}",
    year = "2021",
    publisher = "Peter Lang Verlag",
    address = "Bruxelles, Belgium",
    url = "https://www.peterlang.com/document/1104484"
}