1. R.D. Prengaman and H.B. McDonald, U.S. patent 4,229, 271 (October 21, 1980).
2. R.D. Prengaman and H.B. McDonald, U.S. patent 4,230,545 (October 28, 1980).
3. R.D. Prengamanand H.B. McDonald, U.S. patent 4,236,978 (December 2, 1980).
4. R.D. Prengaman and H.B. McDonald, Lead-Zinc 90, ed. T.S. Mackey and R.D. Prengaman (Warrendale, PA, TMS, 1990).
5. E.R. Cole, A.Y. Lee, and D.L. Paulson, Electrolytic Method for Recovery of Lead from Scrap Batteries, Bur. Mines Report Rl 8602 (Washington, D.C.: U.S. Bureau of Mines, 1981).