<https://zh.wikihow.com/%E6%89%93%E5%BC%80%E9%9A%BE%E4%BB%A5%E6%8B%A7%E5%BC%80%E7%9A%84%E7%93%B6%E7%9B%96>
<http://www.w3.org/1999/02/22-rdf-syntax-ns#type>
<https://zh.wikihow.com/%E6%89%93%E5%BC%80%E9%9A%BE%E4%BB%A5%E6%8B%A7%E5%BC%80%E7%9A%84%E7%93%B6%E7%9B%96>