R. Alzetta, T. Bubba, R. Le Pera, G. Liberti, G. Preparata, D. Tarantino, Giant Resonances and Low-Mass e+e- Pair Production in Relativistic Heavy Ion Collisions, in S. Costa, S. Albergo, A. Insolia, C. Tuv� ed. "Measuring the size of things in the Universe", Proceedings of CRIS'98 Conference, World Scientific, 1999, p. 234.