http://gigazine.net/news/20150911-optikey/

http://ramenandicon.hatenablog.com/entry/2014/01/06/213707

http://detail.chiebukuro.yahoo.co.jp/qa/question_detail/q11412581

http://dailynewsagency.com/2011/06/04/named-after-peple/

http://readingmonkey.blog45.fc2.com/blog-entry-772.html

http://www.yashirohair.com/news12.htm

http://matome.naver.jp/odai/2139746828816552001

http://matome.naver.jp/odai/2141795803309235701

http://blog.yutokatagami.com/entry/Hygiene_hypothesis

http://ameblo.jp/e-fh/entry-10868283176.html

http://pinefield.k-server.org/usa.htm

https://ja.wikipedia.org/wiki/%E3%82%AF%E3%82%B9%E3%82%B3#.E6.B0.97.E5.80.99

http://tenro-in.com/articles/team/22115

https://ja.wikipedia.org/wiki/%E7%B5%B1%E5%90%88%E5%A4%B1%E8%AA%BF%E7%97%87#.E7.B5.B1.E5.90.88.E5.A4.B1.E8.AA.BF.E7.97.87.E3.82.92.E6.82.A3.E3.81.A3.E3.81.9F.E3.81.A8.E3.81.95.E3.82.8C.E3.82.8B.E8.91.97.E5.90.8D.E4.BA.BA

http://www.excite.co.jp/News/bit/00091179941794.htmlhttps://ja.wikipedia.org/wiki/%E9%BB%84%E9%87%91%E5%BE%8B