1. British Pharmacopoeia, HMSO, London, 1988, pp. 37–38.
2. United States Pharmacopoeia XXII, United States Pharmacopoeial Convention, Rockville, MD, 1990, p. 963.
3. United States Pharmacopoeia XXIII, National Formulary XVIII, 1995, pp. 100–103.
4. United States Pharmacopoeia XXIII, National Formulary XVIII, 1995, pp. 375–379.
5. United States Pharmacopoeia XXIII, National Formulary XVIII, 1995, pp. 1234–1235.