1. Herrmann R.B. and Kijko A. (1983) Bulletin of the Seismol. Soc.of America, vol. 73 pp 1835–1850
2. Nuttli O.W. (1973) Journal of Geophysical Res. 78, pp 876–885
3. Herrmann R.B. and Nuttli O.W. (1982) Bulletin of Seismol. Soc.of America, vol. 72, pp 389–397
4. Nuttli O.W. (1980) Bulletin of the Seismol. Soc.of America,vol. 70,pp 469–486
5. Richter (1958) Elementary Seismology WH Freman and Compagny