1. Sol-Gel Technology, Ed. L. Klein, Noyes Pub., Park Ridge (USA) 1988.
2. C.J. Brinker, G.W. Scherer, Sol-Gel Science, Academic Press, San Diego (1990).
3. J. Livage, M. Henry, C. Sanchez, Progress in Solid State Chemistry, 18:259 (1988).
4. J. Livage, Chem. Mater., 3:578 (1991).
5. M. Henry, J.P. Jolivet, J. Livage, Structure and Bonding, 77:153 (1992).