From

https://web.archive.org/web/20161124054718/http://megalodon.jp/2016-1124-1446-57/https://sites.google.com:443/site/tsukasakuwabara1970/home/links/home-page-archive/sumaries-of-doctoral-dissertation


https://web.archive.org/web/20161124060501/http://www.geocities.jp/ptk20120118/Lecture-research/20161103b-ISSN03890104No54/ma01a.jpg
https://web.archive.org/web/20161124060532/http://www.geocities.jp/ptk20120118/Lecture-research/20161103b-ISSN03890104No54/ma02a.jpg