http://www.news24.jp/articles/2016/12/29/04350336.html http://www.mbs.jp/news/kansai/20161229/00000044.shtml

http://www.sankei.com/west/news/161229/wst1612290064-n1.html

http://www.kanaloco.jp/article/222028

http://repository.dl.itc.u-tokyo.ac.jp/dspace/bitstream/2261/61250/1/ggr037010.pdf

http://www.tokyo-np.co.jp/article/feature/himitsuhogo/iwaneba/list/CK2016121902000165.html