1. Bu'Lock, J.D., Comberbach, M.C., Ghommidh, C., and Williams, P.D. (1984). Chemistry and Industry, June, 432?434.
2. Comberbach, D.M., and Bu'Lock, J. D. (1984). Biotechnol. Let., 6, 129?134
3. Kida, K., Asano, S., Yamadaki, M., Iwasaki, K., Yamaguchi, T., and Sonoda, Y. (1990), J. Ferment. Bioeng., 69, 39?45
4. Kalina, V. (1987). UK Patent, GB 2 199 844 A
5. Kuriyama, H., Seiko, Y., Murakami, T., Kobayashi, H., and Sonoda, Y. (1985), J. Ferment. Technol., 63, 159?165