Hadley, E. J. (1945). The magic powder: : history of the Universal Atlas Cement Company and the cement industry (1ª ed.). New York: G.P. Putnam.
Cita MLA (8 ed.) (Copiar al portapapeles)Hadley, Earl J. The Magic Powder: : History of the Universal Atlas Cement Company and the Cement Industry. 1ª ed. New York: G.P. Putnam , 1945.