1. The Korean Nutrition Society: Recommended Dietary Allowance for Koreans, ed 7. Seoul, Jungangmoonhwasa, 2000.
2. Institute of Medicine: DRI Reference Intakes for Thiamin, Riboflavin, Niacin, Vitamin B6, Folate, Vitamin B12, Pantothenic Acid, Biotin, and Choline. Washington, National Academy Press, 1998.
3. Report on Health and Social Subjects: Dietary Reference Values of Food Energy and Nutrients for the United Kingdom. Report of the Panel on Dietary Reference Values of the Committee on Medical Aspects of Food Policy. London, Her Majesty's Stationery Office, 1991, No 41.
4. Health Service Bureau, Ministry of Health and Welfare: Recommended Dietary Allowances for the Japanese, 6th rev ed. Tokyo, Health and Nutrition Division, 1996.
5. National Health and Medical Research Council: Recommended Dietary Intakes for Use in Australia. Canberra, AGPS, 1991.