1. Bell, E.R.J, and White, E.B. Int. Ind. Biotechnol. 9(3) (1989) 20–26.
2. Didriksen, C. Novel colouring agents. The Colour Conference, Leatherhead FRA (1994) pp. 81–91.
3. Kirsop, B. Chem & Ind. April (1981) 218.
4. Kempler, G.M. Adv. in App. Microbiol. 29 (1983) 29.
5. Ilker, R. In-vitro pigment production: An alternative to color synthesis, Food Technol. 41(4) (1987) 70–72.