L. René Valadon was the brother-in-law of Etienne Boussod, and was from 1875 associated with the art dealers, Maison Goupil, in Paris, at 2 place de l'Opéra, and 9 rue Chaptal.
In 1884 Valadon and Lé Boussod founded the firm of Boussod, Valadon et cie. They published illustrated books and prints. They dealt with Whistler's work in Paris for many years. In 1896 Valadon became head of the firm, and from 1897-99 was involved in the direction of Jean Boussod, Manzi, Joyant et cie.
Monneret, Sophie, L'Impressionism et son époqie, Paris, 1978-79; http://www.culture.gouv.fr/GOUPIL (accessed 2004.6).