1. The chemistry of chlorophyll (with special reference to foods);Aronoff;Adv. Food Res.,1953
2. Naturally occurring colouring materials for foods;Coulson,1980
3. Prophyrins and Metallo Porphyrins; Their General, Physical and Coordination Chemistry and Laboratory Methods;Falk,1964
4. Specifications for identity and purity of some food colours, emulsifiers, stabilizers, anti-caking agents, and certain other substances;FAO/WHO,1970
5. Lesser-known food colorants;Francis;Food Technology,1987