http://gigazine.net/news/20150331-tube-enhancer/

http://news.goo.ne.jp/article/mainichi_region/region/mainichi_region-20150401ddlk33040615000c.html

http://www.sankei.com/region/news/150401/rgn1504010052-n1.html

http://headlines.yahoo.co.jp/hl?a=20150403-00000007-okinawat-oki

http://danblog.cocolog-nifty.com/index/2015/04/j-5331.html