1. W. R. Hibbard, Jr., “New Horizons in Extractive Metallurgy,” Extractive Metallurgy Luncheon, AIME Annual Meeting, Los Angeles, California, February 22, 1967.
2. M. B. Bever, “The Recycling of Metals I Ferrous Metals,” Conservation and Recycling, 1, (1976), pp. 55–69.
3. M. B. Bever, “The Recycling of Metals II Nonferrous Metals,” Conservation and Recycling, 1, (1976), pp. 137–147.
4. M. J. Spendlove, “Recycling Trends in the United States: A Review,” Bureau of Mines IC 8711, 1976 p. 25.
5. M. B. Bever, Systems Aspects of Recycling, Conservation and Recycling, 2, 1978, pp. 1–17.