<https://harunikki.com/2023/01/31/%e3%81%af%e3%82%8b%e3%81%a6%e3%82%93%e9%a3%9b%e3%81%b6%ef%bc%81/#article>
<http://www.w3.org/1999/02/22-rdf-syntax-ns#type>
<https://harunikki.com/2023/01/31/%E3%81%AF%E3%82%8B%E3%81%A6%E3%82%93%E9%A3%9B%E3%81%B6%EF%BC%81/>