<https://tsumuji-kenkyujo.net/%e5%a5%b3%e6%80%a7%e3%81%ae%e8%96%84%e6%af%9b%e3%82%92%e7%a2%ba%e5%ae%9f%e3%81%ab%e6%b2%bb%e3%81%99%e6%96%b9%e6%b3%95/>
<http://www.w3.org/1999/02/22-rdf-syntax-ns#type>
<https://tsumuji-kenkyujo.net/%E5%A5%B3%E6%80%A7%E3%81%AE%E8%96%84%E6%AF%9B%E3%82%92%E7%A2%BA%E5%AE%9F%E3%81%AB%E6%B2%BB%E3%81%99%E6%96%B9%E6%B3%95/>