@book { Vingtansdemain,
    title = "Vingt ans demain",
    subtitle = "La nouvelle génération fribourgeoise",
    author = "Jean {Traber}",
    year = "1975",
    publisher = "Peter Lang Verlag",
    address = "Lausanne, Switzerland",
    url = "https://www.peterlang.com/document/1069563"
}