http://gigazine.net/news/20140828-older-sleep-short/

http://gigazine.net/news/20140828-brainwave-transmission/

http://headlines.yahoo.co.jp/hl?a=20140828-00050121-yom-soci

http://www3.nhk.or.jp/news/html/20140829/k10014173731000.html

http://sankei.jp.msn.com/affairs/news/140830/trl14083006000001-n1.htm