https://rocketnews24.com/2017/10/13/968592/

http://www.gov-online.go.jp/useful/article/201710/1.html

http://www.asahi.com/articles/ASKBH44KKKBHIIPE002.html

https://headlines.yahoo.co.jp/hl?a=20171016-00000533-san-soci

https://this.kiji.is/292572342947054689