http://news.livedoor.com/article/detail/9194109/

http://headlines.yahoo.co.jp/hl?a=20150415-00000079-jij-int

http://www.cinra.net/special/vol39/sp39_p4.php

http://www.jiji.com/jc/c?g=soc&k=2015041600817

http://bylines.news.yahoo.co.jp/watanabeteruhito/20150416-00044872/