1. Color: The specialized approach for the food manufacturer;Allman;Flavor Ind.,1973
2. Les colorants alimentaires: Toujours inutiles, parfois dangereux;Apfelbaum;Concours Med.,1977
3. Naturally occurring colorants;Auslander;Drug Cosmet. Ind. Nov.,1977
4. Naturliche Farbstoffe;Bayer,1965
5. “The Natural Pigments.”;Bentley,1960