1. Pharmacopoeia of India, pp.334, 413. Ministry of Health and Family Welfare, Government of India, New Delhi, 1985.
2. British Pharmacopoeia, Vol. II, pp. 974, 992. Her Majesty's Stationery Office, London, 1988.
3. United States Pharmacopoeia, 1985, p. 880. The United States Pharmacopoeial convention, New York, 1985.
4. Nachweis aromatischer Nitrogruppen über die Hydroxylaminstufe