Effect of Self-defocusing in thin films of close –packed CdS Nanocrystals Yu P. Rakovich, M.V. Artmyev, A. M. Almeida, A.G. Rolo, M.J.M. Gomes, M. Belsley “Nanomeeting-99, Conference on “Physics, Chemistry and Application of Nanostructure”, 17-21 Maio de 1999, Minsk, Belarus. http://www.bsuir.edu.by/nano/nanomeeting/99/index.html