@book { ProblemeeuropischerKleinsprachen,
    title = "Probleme europäischer Kleinsprachen",
    author = "Roland {Marti}",
    year = "1990",
    publisher = "Biblion",
    address = ", Germany",
    doi = "10.3726/b12999",
    url = "https://www.peterlang.com/document/1067340"
}