<https://scatikuiku.com/2021/10/03/%e3%81%8a%e3%81%aa%e3%82%89-%e3%81%be%e3%82%93%e5%b1%81/>
<http://www.w3.org/1999/02/22-rdf-syntax-ns#type>
<https://scatikuiku.com/2021/10/03/%E3%81%8A%E3%81%AA%E3%82%89-%E3%81%BE%E3%82%93%E5%B1%81/>