1. Adrian DC (1986) In: Trace Elements in the Terrestrial Environment. Springer-Verlag, Berlin Heidelberg New York Tokyo, Kap 12
2. Allaway WH (1968) In: Hemphill DD (Hrsg) Trace Substances in Environmental Health. Univ of Missouri, Columbia/MO, S 181
3. Rosenfeld I, Beath OA (1964) Selenium: Geobotany, Biochemistry, Toxicity and Nutrition. Academic Press, New York
4. Beath OA, Draize JH, Eppson HF (1932) Wyoming Agr Expt Sta Bull 189: 1
5. Miller JT, Byers HG (1937) J Agric Sci 42: 182