1. A. C. M. Wu and W. A. Bough, in “Proceeding of the First International Conference on Chitin and Chitosan,” MIT Sea Grant Program, Massachusetts, 1978, pp. 88–102.
2. R. A. A. Muzzarelli, in “Proceeding of the Second International Conference on Chitin and Chitosan,” The Japanese Society of Chitin and Chitosan, Tottori, 1982, pp. 183–186.