<https://akinagayasuzi.com/2020/08/25/%e5%8d%b1%e9%99%ba%e3%81%aa%e6%9a%91%e3%81%95-2/>
<http://www.w3.org/1999/02/22-rdf-syntax-ns#type>
<https://akinagayasuzi.com/2020/08/25/%E5%8D%B1%E9%99%BA%E3%81%AA%E6%9A%91%E3%81%95-2/>