<https://chooose.blog/2021/06/04/%e3%82%b7%e3%83%aa%e3%82%b3%e3%83%b3%e8%a3%bd%e8%aa%bf%e7%90%86%e3%82%b9%e3%83%97%e3%83%bc%e3%83%b3/>
<http://www.w3.org/1999/02/22-rdf-syntax-ns#type>
<https://chooose.blog/2021/06/04/%E3%82%B7%E3%83%AA%E3%82%B3%E3%83%B3%E8%A3%BD%E8%AA%BF%E7%90%86%E3%82%B9%E3%83%97%E3%83%BC%E3%83%B3/>