@book { GrundfrageneinesSdosteuropasprachatlas,
    title = "Grundfragen eines Südosteuropasprachatlas",
    author = "Helmut {Schaller}",
    year = "2001",
    publisher = "Biblion",
    address = ", Germany",
    doi = "10.3726/b12878",
    url = "https://www.peterlang.com/document/1067247"
}