1. European Food Safety Authority (2007) Opinion of the scientific panel on dietetic products, nutrition and allergies (NDA) on a request from the Commission related to the tolerable upper intake level of nickel, EFSA Journal. Available at: http://www.efsa.europa.eu/en/efsajournal/pub/146.htm (accessed on 20 December 2012).
2. European Food Safety Authority (2008) Conclusion regarding the peer review of the pesticide risk assessment of the active substance copper (I), copper (II) variants namely copper hydroxide, copper oxychloride, tribasic copper sulfate, copper (I) oxide, Bordeaux mixture. EFSA Scientific Report. Conclusion on the peer review of copper compounds, vol. 187, pp. 1–101. Available at: http://www.efsa.europa.eu/de/scdocs/doc/187r.pdf (accessed on 24 December 2012).
3. Scientific opinion on the safety of chromium picolinate as a source of chromium added for nutritional purposes to foodstuff for particular nutritional uses and to foods intended for the general population;EFSA Journal,2010
4. Joint Food and Agriculture Organization/World Health Organization Expert Committee on Food Additives (JECFA) (2011) Summary and Conclusions of the Seventy-fourth meeting. Available at: http://www.who.int/foodsafety/chem/jecfa/publications/reports/en/index.html (accessed on 25 December 2012).
5. Trace Elements in Human Nutrition,1996