1. Vitamins in Human Health and Disease;Basu,1996
2. http://www.merck.com/pubs/manual/section1/chapter3/3a.htm.
3. The United States Pharmacopeia, 25th revision, United States Pharmacopeial Convention, Rockville, MD, 2002, General Chapter 〈1225〉, pp. 2439–2442.
4. http://www.pharmacopoeia.co.uk/britphar/bpfrs.htm.
5. Merck Index, 12th ed., Merck, New York, 1996, p. 715.