<https://yuensang.com/%e9%ab%98%e5%b3%b6%e6%98%93%e6%96%b7-%e7%81%ab%e5%a4%a9%e5%a4%a7%e6%9c%89%e4%b8%8a%e7%88%bb/>
<http://www.w3.org/1999/02/22-rdf-syntax-ns#type>
<https://yuensang.com/%E9%AB%98%E5%B3%B6%E6%98%93%E6%96%B7-%E7%81%AB%E5%A4%A9%E5%A4%A7%E6%9C%89%E4%B8%8A%E7%88%BB/>