*1:See also http://d.hatena.ne.jp/sumita-m/20140217/1392601359 http://d.hatena.ne.jp/sumita-m/20150730/1438223216 http://d.hatena.ne.jp/sumita-m/20161015/1476517356 http://d.hatena.ne.jp/sumita-m/20170321/1490117707 https://sumita-m.hatenadiary.com/entry/20170511/1494477182 https://sumita-m.hatenadiary.com/entry/2020/01/07/090924 https://sumita-m.hatenadiary.com/entry/2020/01/11/024638
