<https://kairo-u.com/%e3%81%a7%e3%82%93%e3%81%99%e3%81%91%e7%a5%ad%e3%82%8a-1%e6%97%a5%e7%9b%ae/>
<http://www.w3.org/1999/02/22-rdf-syntax-ns#type>
<https://kairo-u.com/%E3%81%A7%E3%82%93%E3%81%99%E3%81%91%E7%A5%AD%E3%82%8A-1%E6%97%A5%E7%9B%AE/>