1. The Merck Index: An Encyclopedia of Chemicals, Drugs and Biologicals, Cambridge: Cambridge Univ. Press, 2001, 13th ed.
2. Dandiya, P.C. and Kilkarni, S.K., Introduction to Pharmacology, Delhi: Vallabh Prakashan 2008, 7th ed., p. 265.
3. Bardou, M., Rev. Prat., 2001, vol. 51, no. 7, p. 789.
4. British Pharmacopoeia, London: The British Pharmacopoeia Commission, 2009, p. 2091 and 5068.
5. Soykan, I., Sarosiek, I., Shifflett, J., Wooten, G.F., and McCallum, R.W., Mov. Disord., 1997, vol. 12, p. 952.