Empirical Equations for the Prediction of the Significant, Bracketed, and Uniform Duration of Earthquake Ground Motion
Bommer, J. J., P. J. Stafford, and J. E. Alarcon 2009, "Empirical Equations for the Prediction of the Significant, Bracketed, and Uniform Duration of Earthquake Ground Motion," Bulletin of the Seismological Society of America, 99(6), 3217-3233.
Abstract available at http://bssa.geoscienceworld.org/cgi/content/abstract/99/6/3217.