1. Evidence of dietary copper and zinc deficiences;Klevay;JAMA,1979
2. Zinc nutrition in United States;Sandstead;Am J Clin Nutr,1973
3. Recommended Dietary Allowances, 8th ed, National Academy of Sciences, National Research Council, pp 95–96, 99–101
4. Trace elements in human and animal nutrition;Underwood,1977
5. Trace elements in human and animal nutrition;Underwood,1977