1. 1) National Institute of Population and Social Security Research：Japan's future population Result Report, 2017 (in Japanese) 国立社会保障・人口問題研究所：日本の将来推計人口結果報告書, 2017
2. 2) Ministry of Agriculture, Forestry and Fisheries：Annual Report on Food, Agriculture and Rural Areas, 2006 (in Japanese) 農林水産省：食料・農業・農村白書, 2006
3. 3) Ministry of Land, Infrastructure and Transport : Investigation report on the village situation for the National Spatial Planning, 2007.3 (in Japanese) 国土交通省：国土形成計画策定のための集落の状況に関する調査 報告書, 2007.3
4. 4) Ministry of Land, Infrastructure and Transport : Tips for thinking about the future of small and aging villages, 2012.3 (in Japanese) 国土交通省：小規模・高齢化する集落の将来を考えるヒント集, 2012.3
5. 5) Yoshinobu Kikuchi, Shinji Nojima : Survey on The Functions of The Aging Villages in Intermediate and Mountainous Areas, The memoirs of the Research and Education Center for Regional Environment, University of Fukui "Nature and the environment of the Japan Sea area", No. 15, pp. 107-114, 2008 (in Japanese) 菊地吉信, 野嶋慎二：中山間高齢化集落の集落機能に関する調査研究, 福井大学地域環境研究教育センター研究紀要, 日本海地域の自然と環境, No. 15, pp. 107-114, 2008