URL https://www.researchgate.net/profile/Ryuichi_Shinjo/publication/241713018/figure/download/fig3/AS:393117262991362@1470737867340/Quaternary-map-of-north-central-part-of-Okinawa-jima-O1.png
URL2 https://www.researchgate.net/figure/Quaternary-map-of-north-central-part-of-Okinawa-jima-O1_fig3_241713018
