1. W. O. ROBINSON, H. C. DUDLEY, K. T. WILLIANS, H. G. BYERS, Ind. Eng. Chem., Anal. Ed. 6 (1934) 274.
2. Booz-Allen Applied Research, Inc., A Study of Hazardous Waste Materials, Hazardous Effects and Disposal Methods Report PB 221 466, Springfield, Va., Nat. Tech. Information service, July, 1973.
3. National Research Council, Selenium, Report EPA-600/1-76-014, Research Trangle Park, N. C., Environmental Protection Agency, Jan. 1976.
4. Marshal Sitting; Toxic Metals, Pollution Control and Worker Protection; NDC, Pollution Technology Review, No. 30 (1976).
5. J. H. WATKINSON, Anal. Chem., 32 (1960) 981.