<https://lmf9sotk.pixnet.net/blog/post/333561082-%e4%bb%80%e9%ba%bc%e4%bf%a1%e7%94%a8%e5%8d%a1%e5%84%aa%e6%83%a0%e6%9c%80%e5%a4%9a-%e9%8a%80%e8%a1%8c%e4%bf%a1%e7%94%a8%e5%8d%a1%e5%84%aa%e6%83%a0%e6%af%94%e8%bc%83-%e6%a1%83>
<http://www.w3.org/1999/02/22-rdf-syntax-ns#type>
<https://lmf9sotk.pixnet.net/blog/post/333561082>