1. Wortmann, F.J.; Kure, N. J. Soc. Cosmet. Chem. 41:123 (1990).
2. Salce, L.; Savaides, A.; Schultz, T. In 8th International Hair-Science Symposium, Kiel, Germany (German Wool Res. Inst. Publ. Abstracts.) (1992) .
3. Feughelman, M. J. Soc. Cosmet. Chem. 42:129 (1991).
4. Cleland, W. Biochemistry 3:480 (1964) .
5. Fruton, J.S.; Clark, H.T. J. Biol. Chem. 106:667 (1934).