iii. Bibliography

1. North West water authority, Water Standards Tables, 1994
2. Wood & Holliday, Inorganic Chemistry - 3rd Ed., pp. 328
3. Belcher & Nutten, Qualitative Inorganic Chemistry - 2nd Ed.
4. Vogel, A. Qualitative Inorganic Chemistry - 3rd Ed.
5. Literature cited value (see original methodology)
6. H.S.E. Chromium, 1983
7. Russian Medical Journal, Russian Health, 1991, pp.32, 61
8. . B.M.A. Toxic effects of transition elements on the internal organs. 1961
9. Adapted from Hermann, M.S. J. Chem Ed. 71, 1994, pp. 323-324
10. Lunn G, Samsone, E.B., J. Chem. Ed. 66, 1989, pp. 443