1. Hanson, D., Chem. Eng. News, 1988, vol. 4, p. 38.
2. Hileman, B., Chem. Eng. News, 1988, vol. 18, p. 24.
3. Heldman, E., Balan, A., Horowitz, O., Ben-Zion, S., and Torten, M., FEBS Lett., 1985, vol. 180, no. 2, p. 243.
4. Clark, E.R. and Quazi, I.A., Analyst, 1990, vol. 105, p. 564.
5. Derek, S., Farrington, F.J., Lovett, P., and Lynch, V., Analyst, 1993, vol. 108, p. 353.