1. Martindale, The Extra Pharmacopoeia, 31st ed., Royal Pharmaceutical Society, London, 1996, p. 1240.
2. British Pharmacopoeia, 17th ed., Stationery Office, Department of Health, London, UK, 1999, pp. 1271–1274, 2086–2088.
3. European Pharmacopoeia, 3rd ed., European Department for the Quality of Medicines, Council of Europe, Strasbourg, 1997, pp. 1460–1464.
4. United States Pharmacopeia, 24th ed., United States Pharmacopeial Convention, Twinbrook Parkway, Rockville, MD, USA, 2000, pp. 1516–1517.
5. The Japanese Pharmacopeia, 13th ed., The Society of Japanese Pharmacopeia, Tokyo, Japan, 1996, pp. 899–990.