Enquête sur l'histoire et les changements dramatiques du 20e siècle et l'émergence de la foi baha'ie de l'obscurité. Traduction de Century of Light.
This is an "official" translation, prepared by the French Panel named by the Universal House of Justice and published by the French publishing trust, la Maison d'éditions bahá'íes.
See also Bibliothèque baha'ie. See also English original.