1. World seismicity maps compiled from ESSA;Barazangi,1969
2. Geology of Ishigaki-shima, Ryukyu-retto;Foster,1965
3. Geologic structure of the Ryukyu arc: Chishitsugaku Zasshi;Koto;Geol. Soc. Tokyo J.,1897
4. The Sakawa orogenic cycle and its bearing on the origin of the Japanese Islands;Kobayashi;Tokyo Univ. Fac. Sci. J.,1941
5. Pre-Miocene basement complex of Okinawa, and the tectonic belts of the Ryukyu Islands;Konishi,1963