1. AESGP (Association of the European Self-Medication Industry) 2003 Ensuring adequate vitamin and mineral content in food supplements http://ec.europa.eu/food/food/labellingnutrition/nutritionlabel/aesgp_en.pdf
2. Evaluating food fortification options: general principles revisited with folic acid;Crane;American Journal of Public Health,1995
3. EC (European Commission) 2012 Guidance document for competent authorities for the control of compliance with EU legislation with regard to the setting of tolerances for nutrient values declared on a label http://ec.europa.eu/food/food/labellingnutrition/nutritionlabel/guidance_tolerances_december_2012.pdf