03-09-2011, 01:23 PM
I'm looking for this article. Thanks for your interest.
Somerville, P. G., Smith, N. F., Graves, R. W., and Abrahamson, N. A., 1997, "Modification of Empirical Strong Ground Motion Attenuation Relations to Include the Amplitude and Duration Effects of Rupture Directivity." Seismological Research Letters, Vol. 68, No.1, pp.199-222
Somerville, P. G., Smith, N. F., Graves, R. W., and Abrahamson, N. A., 1997, "Modification of Empirical Strong Ground Motion Attenuation Relations to Include the Amplitude and Duration Effects of Rupture Directivity." Seismological Research Letters, Vol. 68, No.1, pp.199-222