<https://biung.pixnet.net/blog/post/27429937-%e7%8e%8b%e5%ae%8f%e6%81%a9%e6%96%b0%e5%b0%88%e8%bc%af--iphone%e4%bd%94%e6%9c%89%e8%88%89%e8%b6%b3%e8%bc%95%e9%87%8d%e7%9a%84%e5%9c%b0%e4%bd%8d%21%21%21>
<http://www.w3.org/1999/02/22-rdf-syntax-ns#type>
<https://biung.pixnet.net/blog/post/27429937>