<https://www.amii-ozaki.com/post/\u591C\u8B66\u3063\u3066\u3002\u7B11>
<http://www.w3.org/1999/02/22-rdf-syntax-ns#type>
<https://www.amii-ozaki.com/post/%E5%A4%9C%E8%AD%A6%E3%81%A3%E3%81%A6%E3%80%82%E7%AC%91>