<https://blog.ulifestyle.com.hk/article/chingyw/2792409/\u751F\u65E5\u9858\u671B>
<http://www.w3.org/1999/02/22-rdf-syntax-ns#type>
<https://blog.ulifestyle.com.hk/article/chingyw/2792409/%E7%94%9F%E6%97%A5%E9%A1%98%E6%9C%9B>