1. Allan, J. E. (1971)The Preparation of Samples for Analysis by Atomic Absorption Spectroscopy (California: Varian Techtron Ltd).
2. Achyuthan, K. E., Ranganatha Rao, K. and Ramachandran, L. K. (1980)Indian J. Biochem. Biophys.,17, 228.
3. Achyuthan, K. E. and Ramachandran, L. K. (1980)Proc. Indian Natl. Sci. Acad.,B46, 603.
4. Achyuthan, K. E, and Ramachandran, L. K.(1981)Biosci.,3, 149.
5. Brunisholz, G. (1957)Chimia (Switz.),11, 363; C. A.52, 6048g.