1. Special Publication No. 73;RC Massey,1989
2. Pennington JA (1988) Food Add Contamn 5:161?232
3. Candrian U (1985) Mitt Geb Lebensmittelunters Hyg 76:570?608
4. Ministry of Agriculture, Fisheries and Food, London (1985). Survey of Aluminium, Antimony, Chromium, Cobalt, Indium, Nickel, Thallium and Tin in Food. Food Surveillance Paper No. 15:3?7
5. Knutti R, Zimmerli B (1985) Mitt Geb Lebensmittelunters Hyg 76:206?232