<https://jiyuland.com/%e5%8f%a3%e3%82%b3%e3%83%9f%e3%80%80%e4%b8%96%e7%95%8c%e3%81%ae%e5%b1%b1%e3%81%a1%e3%82%83%e3%82%93/>
<http://www.w3.org/1999/02/22-rdf-syntax-ns#type>
<https://jiyuland.com/%E5%8F%A3%E3%82%B3%E3%83%9F%E3%80%80%E4%B8%96%E7%95%8C%E3%81%AE%E5%B1%B1%E3%81%A1%E3%82%83%E3%82%93/>