1. 1943.Allowable Concentrations of MercuryVol. 8, 2 Z 37.8 Committee of the US American Standards Institute
2. 1960.Mineral Facts and Problems, 511–519. US Dept of Interior, Bureau of Mines. Bulletin 585
3. Beeson, P.B. and McDermott, W. 1963.Textbook of Medicine, 11, 1778–1781. Philadelphia: W. B. Saunders Co.