1. The Martindle Extra Pharmacopoeia, 31st ed., p. 438.
2. The British Pharmacopoeia, British Pharmacopoeial Commission, London, 1993, p. 1314.
3. The Martindle Extra Pharmacopoeia, 31st ed., p. 1237.
4. The British Pharmacopoeia, British Pharmacopoeial Commission, London, 1993, p. 1768–1769.