<https://hotoricafe.jp/2020/03/01/%e6%9f%90%e5%9b%bd%e3%81%ae%e3%83%97%e3%83%aa%e3%83%b3%e3%82%bb%e3%82%b9/#webpage>
<http://www.w3.org/1999/02/22-rdf-syntax-ns#type>
<https://hotoricafe.jp/2020/03/01/%E6%9F%90%E5%9B%BD%E3%81%AE%E3%83%97%E3%83%AA%E3%83%B3%E3%82%BB%E3%82%B9/>