@book { JeandeBertier18771926,
    title = "Jean de Bertier (1877-1926) ",
    subtitle = "Un aristocrate à la frontière. France, Allemagne, Luxembourg",
    author = "Stéphane {Einrick}",
    year = "2025",
    publisher = "Peter Lang Verlag",
    address = "Lausanne, Switzerland",
    url = "https://www.peterlang.com/document/1466125"
}