1. Y. Nakamura, Clear Identification of Fundamental Idea of Nakamura’s (System and Data Research Co. Ltd., l3-25-3 Fujimidai, Kunitachi-shi, Tokyo, 2000).
2. Y. Nakamura, “On the H/V Spectrum,” in The 14th World Conference on Earthquake Engineering (Beijing, China, 2008).
3. Y. Nakamura, “Seismic Vulnerability Indices for Ground and Structures Using Microtremor,” in World Congress on Railway Research, (Florence, 1997).
4. http://earthquake.usgs.gov/earthquakes/search/
5. http://earthquake.usgs.gov/hazards/apps/vs30/custom.php