1. R M Christie, Colour Chemistry, Royal Society of Chemistry, June 2001.
2. W Herbst and K Hunger, Industrial Organic Pigments, Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim, Third Edition, 2004.
3. Peter Bamfield, Chromic Phenomena, The Technological Applications of Colour Chemistry, The Royal Society of Chemistry, 2001.
4. John Shore, Colorants and Auxiliaries, Society of Dyers and Colourists, Vols. 1 and 2, 2002.
5. Heinrich Zollinger, Diazo Chemistry, VCH Verlagsgesellschaft mbH, Weinheim, Germany, Vol. 1, 1993; Vol. 2, 1995.