@book { GeorgMayerzum60Geburtstag,
    title = "Georg Mayer zum 60. Geburtstag",
    author = "Ursula {Bieber} and Alois {Woldan}",
    year = "1991",
    publisher = "Biblion",
    address = ", Germany",
    doi = "10.3726/b12751",
    url = "https://www.peterlang.com/document/1067145"
}