http://www.tokyo-np.co.jp/article/economics/list/201809/CK2018092902000129.html

https://www.news-postseven.com/archives/20180930_771685.html

https://headlines.yahoo.co.jp/hl?a=20180929-00008615-bengocom-soci

http://www.nnn.co.jp/dainichi/news/180928/20180928087.html

https://matome.naver.jp/odai/2133776052335294501