@book { DieDeutscheninUngarn,
    title = "Die Deutschen in Ungarn",
    author = "Georg {Brunner}",
    year = "1989",
    publisher = "Biblion",
    address = ", Germany",
    doi = "10.3726/b12560",
    url = "https://www.peterlang.com/document/1067012"
}