http://book.asahi.com/reviews/column/2015050300001.html

http://blog.livedoor.jp/schulze/archives/52118203.html

http://headlines.yahoo.co.jp/hl?a=20150509-00000019-asahi-pol

http://www.sankei.com/region/news/150509/rgn1505090021-n1.html

http://news.goo.ne.jp/article/sankei/region/sankei-rgn1505090047.html