1. P. Paldi, V. Achilli, F. Mulargia andF. Broccio:Bull. Geodes., in press (1983).
2. M. Caputo, L. Pieri, M. Barbarella, A. Gubellini, P. Russo andR. Console:Tectonophysics,74, 147 (1981).
3. C. Gasparini, G. Iannaccone, P. Scandone andR. Scarpa:Tectonophysics,84, 267 (1982).
4. F. Mulargia, P. Baldi, V. Achilli andF. Broccio:Geophys. J. R. Astron. Soc., in press (1983).
5. F. Mulargia andE. Boschi: related seismicity.Proc. S.I.F., to be published.