<https://www.hiiragisouren.com/post/\u304A\u4ED5\u4E8B-\u534A\u4E16\u754C\u306E\u65C5>
<http://www.w3.org/1999/02/22-rdf-syntax-ns#type>
<https://www.hiiragisouren.com/post/%E3%81%8A%E4%BB%95%E4%BA%8B-%E5%8D%8A%E4%B8%96%E7%95%8C%E3%81%AE%E6%97%85>