1. EC (European Commission) 2003a Opinion of the Scientific Committee for Animal Nutrition on the use of copper in feedingstuffs ec.europa.eu/food/fs/sc/scan/out115_en.pdf
2. EC (European Commission) 2003b Opinion of the Scientific Committee on Food on the Tolerable Upper Intake Level of Copper ec.europa.eu/food/fs/sc/scf/out176_en.pdf
3. EC (European Commission) 2004 Reports on tasks for Scientific Cooperation (SCOOP) ec.europa.eu/food/food/chemicalsafety/contaminants/scoop_3-2-11_heavy_metals_report_en.pdf
4. Opinion of the Scientific Panel on Additives and Products or Substances used in Animal Feed on the safety and efficacy of the product Sel-Plex®2000 as a feed additive according to Regulation (EC) No 1831/2003;EFSA (European Food Safety Authority);The EFSA Journal,2006
5. Opinion of the Scientific Panel on Additives and Products or Substances used in Animal Feed on the safety and efficacy of the product Selenium enriched yeast (Saccharomyces cerevisiae NCYC R397) as a feed additive for all species in accordance with Regulation (EC) No 1831/2003;EFSA (European Food Safety Authority);The EFSA Journal,2006