@book { NationaleGrenzeninEuropa,
    title = "Nationale Grenzen in Europa",
    author = "Christian {Banse} and Holk {Stobbe}",
    year = "2021",
    publisher = "Peter Lang Verlag",
    address = "Berlin, Germany",
    url = "https://www.peterlang.com/document/1097687"
}