http://www.nikkei-science.com/201709_054.html

http://www.yomiuri.co.jp/national/20170816-OYT1T50001.html

https://headlines.yahoo.co.jp/hl?a=20170816-00010005-chibatopi-l12

http://www.tokyo-np.co.jp/article/education/edu_national/CK2017081502000173.html

http://www.jomo-news.co.jp/ns/6615027611301536/news.html