<https://e610706.pixnet.net/blog/post/9605419-%e9%bb%83%e9%87%91%e5%a6%82%e6%84%8f>
<http://www.w3.org/1999/02/22-rdf-syntax-ns#type>
<https://e610706.pixnet.net/blog/post/9605419-%E9%BB%83%E9%87%91%E5%A6%82%E6%84%8F>