1. Comparison of tidal changes of ground strain and groundwater observed at crustered boreholes in Tono region, central Japan;Asai;J. Geod. Soc. Japan,2001
2. Co-seismic strain-steps associated with the 2004 off the Kii peninsula earthquakes—observed with Ishii-type borehole strainmeters and quartz-tube extensometers;Asai;Earth Planets Space,2005
3. Ishii, H., Yamauchi, T., Asai, Y., Ohkubo, M., Matsumoto, S., Aoki, H., 2003. Continuous multi-component monitoring of crustal activities by a newly developed instrument installed in a 1200m depth borehole—the deepest multiple observation in the world consisting of stress, strain, tilt, seismic waves, geomagnetism, temperature. Paper presented at IUGG XXIII General Assembly. Int. Union of Geod. and Geophys., Sapporo, Japan.
4. JNC, 2003. Annual Report of Research and Development on HLW Geological Disposal in 2002. JNC Tech Rep., JNC TN1400 2003-004 (in Japanese).