"Extrait de la Revue des Deux Mondes livraison du 1er janvier 1846."
Reproduction of original from Kress Library of Business and Economics, Harvard University.
Goldsmiths'-Kress no. 34634.18.
Electronic reproduction. Farmington Hills, Mich. : Thomson Gale, 2005. Available via the World Wide Web. Access limited to licensing agreements.