<https://www.balabibi.com/blog/tag/%e6%b8%85%e6%bd%94%e7%89%99%e9%bd%92/#webpage>
<http://www.w3.org/1999/02/22-rdf-syntax-ns#type>
<https://www.balabibi.com/blog/tag/%E6%B8%85%E6%BD%94%E7%89%99%E9%BD%92/>