1. Chiba Prefecture (1976) Basis survey of land classification, Otaki. Chiba Prefecture, Chiba
2. Fukamachi K, Oku H, Nakashizuka T (2001) The change of a satoyama landscape and its causality in Kamiseya, Kyoto Prefecture, Japan between 1970 and 1995. Landsc Ecol 16:703–717
3. Geological Survey of Japan (2004) Digital geological maps of Japan 1:200,000, Kanto-Koshinetsu and Izu-Ogasawara Islands. Geological Survey of Japan, Tsukuba
4. Geological Survey of Japan (2005) Digital geological maps of Japan 1:200,000, Eastern and central part of Chugoku, and Shikoku. Geological Survey of Japan, Tsukuba
5. Hiroshima Prefecture (1985) Basis survey of land classification, Takehara. Hiroshima Prefecture, Hiroshima