Source: https://www.histoire-geo.eu/wp-content/uploads/2020/03/La-difficile-entr%C3%A9e-dans-l%E2%80%99%C3%A2ge-d%C3%A9mocratique-la-deuxi%C3%A8me-r%C3%A9publique-et-le-second-empire.pdf