1. Ebelmen, J.J., Ann. 57, 331 (1846).
2. Roy, R., J. Am. Ceram. Soc. 39, 145 (1956).
3. Sol-Gel Technology for Thin Film, Fibers, Preforms, Electronics and Speciality Shapes, edited by L.C. Klein (Noyes, Park Ridge, N.J. 1988).
4. Brinker, C.J. and Scherer, G.W., Sol-Gel Science (Academic Press, San Diego, 1990).
5. Roy, R.A. and Roy, R., Mat. Res. Bull 19, 169 (1984).