1. J.E.F. Reynolds, Martindale, The Extra Pharmacopoeia, 30th Edition, The Pharmaceutical Press, London, 1993.
2. American Hospital Formulary Service 98, Drug Information, American Society of Health-System Pharmacists, Bethesda, MD, 1988.
3. R.E. Shirmer, Modern Methods of Pharmaceutical Analysis, Vol. I, CRC Press, Boca Raton, FL, 1982, pp. 83–91.
4. Zur Kenntnis der Pyridinfarbstoffe