<https://kuwanokazuya.com/%e3%82%b3%e3%83%ad%e3%83%8a%e5%85%a8%e7%84%b6%e3%81%b8%e3%83%bc%e3%81%8d/>
<http://www.w3.org/1999/02/22-rdf-syntax-ns#type>
<https://kuwanokazuya.com/%E3%82%B3%E3%83%AD%E3%83%8A%E5%85%A8%E7%84%B6%E3%81%B8%E3%83%BC%E3%81%8D/>