<https://pai0916.pixnet.net/blog/post/348844936-%e7%bf%94%e7%bf%bc%e9%80%9a%e8%a8%8a-%e4%b8%ad%e5%9c%8b%e4%b8%8a%e7%b6%b2%e5%85%8d%e7%bf%bb%e7%89%86%e8%b6%85%e4%be%bf%e5%88%a9-%e5%b9%b3%e6%bd%ad-%e7%a6%8f%e5%b7%9e%e5%9b%9b>
<http://www.w3.org/1999/02/22-rdf-syntax-ns#type>
<https://pai0916.pixnet.net/blog/post/348844936>