<https://cderty2003.pixnet.net/blog/post/52199696-%e3%80%8c%e5%9b%9b%e5%8d%8a%e3%80%8d%e5%81%a5%e5%ba%b7%e7%98%a6>
<http://www.w3.org/1999/02/22-rdf-syntax-ns#type>
<https://cderty2003.pixnet.net/blog/post/52199696>