The paper Empirical site classification of seismological stations in Chile using horizontal-to-vertical spectral ratios determined from recordings of large subduction-zone earthquakes of researchers Shuo Yang, George Mavroeidis, Juan Carlos de la Llera, Alan Poulos, Paula Aguirre, S. Rahpeyma, T. Sonnemann, and B. Halldorsson was published online in the journal Soil Dynamics and Earthquake Engineering. You can read it from the journal website here or you can contact the authors for a copy (see People).