<https://hoikuen.love/2021/04/12/%e8%ba%ab%e4%bd%93%e6%b8%ac%e5%ae%9a%e3%82%92%e3%81%97%e3%81%be%e3%81%97%e3%81%9f/>
<http://www.w3.org/1999/02/22-rdf-syntax-ns#type>
<https://hoikuen.love/2021/04/12/%E8%BA%AB%E4%BD%93%E6%B8%AC%E5%AE%9A%E3%82%92%E3%81%97%E3%81%BE%E3%81%97%E3%81%9F/>