<https://rikimarunosuke.net/2023/07/12/%e6%b3%95%e4%ba%ba%e9%96%8b%e8%a8%ad%e3%83%bb%e4%bc%9a%e7%a4%be%e3%81%ae%e4%bd%9c%e3%82%8a%e6%96%b9/#article>
<http://www.w3.org/1999/02/22-rdf-syntax-ns#type>
<https://rikimarunosuke.net/2023/07/12/%E6%B3%95%E4%BA%BA%E9%96%8B%E8%A8%AD%E3%83%BB%E4%BC%9A%E7%A4%BE%E3%81%AE%E4%BD%9C%E3%82%8A%E6%96%B9/>