<https://icelog.net/%e3%81%84%e3%81%a1%e3%81%94%e3%83%81%e3%83%a7%e3%82%b3%e3%83%9f%e3%83%b3%e3%83%88-2021/>
<http://www.w3.org/1999/02/22-rdf-syntax-ns#type>
<https://icelog.net/%E3%81%84%E3%81%A1%E3%81%94%E3%83%81%E3%83%A7%E3%82%B3%E3%83%9F%E3%83%B3%E3%83%88-2021/>