L. Bourget, R. J. P. Corriu, D. Leclercq, P. H. Mutin, A. Vioux, “Preparation of hybrid organic-inorganic gels by non-hydrolytic condensation reactions”, in “Proceedings of the First European Workshop on Hybrid Organic-Inorganic Materials”, 1993, 305, edited by C. Sanchez et F. Ribot Eds, Paris (France).