1. Fisher, R. A. Proc. R. Soc. A217, 295 (1963).
2. Yukutake, T. & Tachinaka, H. Bull. Earthquake Res. Inst., Tokyo 47, 65 (1969).
3. Yukutake, T. & Tachinaka, H. Bull. Earthquake Res. Inst., Tokyo 46, 1027 (1968).
4. Alldredge, L. R. & Hurwitz, L. J. Geophys. 69, 2631 (1964).
5. Stearns, C. O. & Alldredge, L. R. Meth. Comput. Phys. 13, 61 (1973).