1. Savory J, Wills MR (1991) Aluminum. In: Merian E (ed) Metals and their compounds in the environment ? occurrence, analysis and biological relevance. VCH, Weinheim New York Basel Cambridge, pp 715?741
2. Birchall JD, Exley C, Chappell JS, Phillips MJ (1989) Nature 338:146?148
3. Birchall JD, Chappell JS (1988) Clin Chem 34:265?267
4. Carlisle EM (1986) Silicon. In: Mertz W (ed) Trace elements in human and animal nutrition. Academic Press, Orlando, pp 128?133
5. Grasshoff K, Hahn H (1959) Fresenius Z Anal Chem 168:247?263