1. Aluminum Statistical Review for 1999 (Washington, D.C.: The Aluminum Association, Inc., 2000).
2. C.C. Carr, Alcoa, An American Enterprise (New York: Rinehart and Company, Inc., 1952).
3. W.T. Ennor, U.S. patent 2,301,027 (1942).
4. J.D. Edwards, F.C. Frary, and Z. Jeffries, The Aluminum Industry, Vol. 2 (New York: McGraw-Hill, 1930).
5. Harold Y. Hunsicker, Alcoa Technical Center (retired), personal communication.