1. NCHS (National Center for Health Statistics) 2005 http://www.cdc.gov/nchs/drugs/htm. Accessed 7 November 2005
2. Federal Interagency Forum on Aging Related Statistics 2005 http://www.agingstats.gov. Accessed 7 November 2005
3. Quantitative safety assessment model for transgenic protein products produced in agricultural crops;Howard;J. Agricul. Environ. Ethics.,2004
4. PEW (Pew Initiative on Food, Biotechnology) 2004 http://pewagbiotech.org/resources/factsheets/
5. Hallman W K Hebden W C Cuite C L 2004