@book { TrkeianteportasDerBeitrittderTrkeizurEuropischenUnion,
    title = "Türkei ante portas – Der Beitritt der Türkei zur Europäischen Union",
    author = "Christian {Bürger}",
    year = "2021",
    publisher = "Peter Lang Verlag",
    address = "Berlin, Germany",
    url = "https://www.peterlang.com/document/1106976"
}