1. The Merck Index — An Encyclopedia of Chemicals, Drugs and Biologicals, 13th edn, Merch, USA, 2001, p. 1256.
2. Goodman and Gilman’s The Pharmacological Basis of Therapeutics, 10th edn, McGraw-Hill, 2001, pp. 1007–1009.
3. British Pharmacopoeia, International edn, Vol. I, HMSO, Cambridge, 2004, pp. 640–641.
4. European Pharmacopoeia, 3rd edn, Council of Europe, France, 1997, pp. 779–780.