<https://www.yasuioffice.com/post/2019/03/06/\u6D77\u5916\u4FDD\u967A>
<http://www.w3.org/1999/02/22-rdf-syntax-ns#type>
<https://www.yasuioffice.com/post/2019/03/06/%E6%B5%B7%E5%A4%96%E4%BF%9D%E9%99%BA>