1. M. K. SCHWARTZ, Cancer Res., 35 (1975) 3481.
2. H. H. SKY-PECK, Clin. Physiol. Biochem., 4 (1986) 99.
3. G. N. SCHRAUZER, The role of trace elements in the etiology of cancer, Trace Element Analytical Chemistry in Medicine and Biology, P. BRATTER, P. SCHRAMEL (Eds), Walter De Gruyter, Berlin, New York, 1980.
4. I. B. WEINSTEIN, NY Acad. Med., 54 (1978) 366.
5. I. L. CAMERON, N. K. R. SMITH, T. B. POOL, R. L. SPARKS, Cancer Res., 40 (1980) 1493.