1. Vitamin & Mineral Deficiency: a Global Progress Report;Adamson,2004
2. Photodegradation of folic acid in aqueous solution;Akhtar;J. Pharm. Biomed. Anal.,1999
3. Method 33.149;AOAC,1984
4. Human Vitamin and Mineral Requirements: Report of a Joint FAO/WHO Expert Consultation Bangkok Thailand;FAO,2002