@book { Lafrancophonie,
    title = "La francophonie",
    subtitle = "Bibliographie analytique de la recherche internationale 1980–2005",
    author = "Jürgen {Erfurt} and Maria {Amelina}",
    year = "2011",
    publisher = "Peter Lang Verlag",
    address = "Berlin, Germany",
    url = "https://www.peterlang.com/document/1107595"
}