1. Martindale, The Extra Pharmacopoeia, 28 ed., The Pharmaceutical Press, London, 1982.
2. Merck Index, 12 ed., Merck & Co. Inc., White House Station, NJ, 1995.
3. British Pharmacopoeia, Her Majesty's Stationary Office, London, 1998.
4. The United States Pharmacopoeia XXII. National Formulary XVII, Rockville, MD, USP convention, Inc., 2000.
5. Titrimetric determinations of some antitubercular drugs by sodium nitrite and N-bromosuccinimide (NBS) using internal indicators;Reddy;Indian Drugs,1982