1. Oral Liquids, British Pharmacopoeia 1998, London, 1998, pp. 1440–1441.
2. 672 Oral liquids, Powders and granulates for the preparation of solutions and suspensions for ingestion, European Pharmacopoeia 1997, German Edition, Frankfurt 1997, p. 1847.
3. Suspensions, p. 1949, Ophthalmic suspensions, p. 1946, United States Pharmacopoeia, 23rd edn., Rockville MD, 1995.
4. The Pharmacopeia of Japan XIIth edition, including Appendices I and II, Tokyo, 1995.
5. International Pharmacopeia, Vols. 1–4, Geneva, 1995.