@book { RudolfBchtoldzum70Geburtstag,
    title = "Rudolf Bächtold zum 70. Geburtstag",
    author = "Peter {Thiergen}",
    year = "1987",
    publisher = "Biblion",
    address = ", Germany",
    doi = "10.3726/b12982",
    url = "https://www.peterlang.com/document/1067326"
}