1. World Health Organization http://www.who.int/mediacentre/factsheets/fs311/en/index.html 2006
2. World Health Organization http://www.who.int/mediacentre/factsheets/fs297/en/index.html 2009
3. Global Alliance for the Prevention of Obesity and Related Chronic Disease http://www.preventionalliance.net/ 2008
4. International Union Against Cancer_(UICC) http://www.uicc.org/index.php?option=com_content&task=view&id=14227&Itemid=356 2008
5. Colquitt JL Picot J Loveman E Clegg AJ. 2009