<https://sanders.jp/blogs/journal/2022-spring-summer-%E5%85%A5%E8%8D%B7%E6%83%85%E5%A0%B1-1>
<http://www.w3.org/1999/02/22-rdf-syntax-ns#type>
<https://sanders.jp/blogs/journal/2022-spring-summer-%E5%85%A5%E8%8D%B7%E6%83%85%E5%A0%B1-1>