<https://yatagarasu-jgc.com/archives/category/jgc%e4%bf%ae%e8%a1%8c%e7%b7%a8/1%e6%9d%b1%e4%ba%ac%e3%83%bb%e4%b8%ad%e9%83%a84%e3%83%ac%e3%82%b0%e4%bf%ae%e8%a1%8c>
<http://www.w3.org/1999/02/22-rdf-syntax-ns#type>
<https://yatagarasu-jgc.com/archives/112>