<https://www.monktalks.net/post/\u65B0\u5E74\u53D1\u8D22\u4EEA\u8F68>
<http://www.w3.org/1999/02/22-rdf-syntax-ns#type>
<https://www.monktalks.net/post/%E6%96%B0%E5%B9%B4%E5%8F%91%E8%B4%A2%E4%BB%AA%E8%BD%A8>