<https://p360130.pixnet.net/blog/post/19502887-%e8%aa%8d%e8%ad%98%e6%8c%87%e6%8f%ae%e5%ae%b6%e7%9a%84%e9%a2%a8%e9%87%87%2873%29-jiri-belohlavek-%e4%bc%8a%e9%87%8c%ef%bc%8e%e8%b2%9d%e6%b4%9b>
<http://www.w3.org/1999/02/22-rdf-syntax-ns#type>
<https://p360130.pixnet.net/blog/post/19502887-%E8%AA%8D%E8%AD%98%E6%8C%87%E6%8F%AE%E5%AE%B6%E7%9A%84%E9%A2%A8%E9%87%87%2873%29-jiri-belohlavek-%E4%BC%8A%E9%87%8C%EF%BC%8E%E8%B2%9D%E6%B4%9B>