@book { FranceAllemagneladifficileconvergence,
    title = "France-Allemagne : la difficile convergence",
    author = " {Hau}",
    year = "2014",
    publisher = "Peter Lang Verlag",
    address = "Lausanne, Switzerland",
    doi = "10.3726/978-3-0352-0294-6",
    url = "https://www.peterlang.com/document/1053196"
}