D. TEODOSIEV, L. ANESTIEV, J. GEORGIEV, N. PETROV, P. TZVETKOV, and H. NIKOLOVA, “Glass-Carbon Bioactive Coatings on a TiO2- Nb2O5 Substrate”, The Annals of “Dunarea de Jos” University of Galati. Fascicle IX, Metallurgy and Materials Science, vol. 33, no. 2, pp. 18-24, Jun. 2010.