http://biz-journal.jp/2017/09/post_20770.html

https://headlines.yahoo.co.jp/hl?a=20171006-00152620-okinawat-pol

https://www.nikkei.com/article/DGXMZO21880970U7A001C1EE9000/

http://www.nri.com/~/media/PDF/jp/opinion/teiki/kinyu_itf/2017/itf_201710_2.pdf

https://headlines.yahoo.co.jp/hl?a=20171006-00172830-nbnv-l23