<https://fanfan-life.com/2016/10/15/%e3%82%84%e3%81%a3%e3%81%b1%e3%82%8a%e8%b1%9a%e9%aa%a8%e3%83%a9%e3%83%bc%e3%83%a1%e3%83%b3/>
<http://www.w3.org/1999/02/22-rdf-syntax-ns#type>
<https://fanfan-life.com/2016/10/15/%E3%82%84%E3%81%A3%E3%81%B1%E3%82%8A%E8%B1%9A%E9%AA%A8%E3%83%A9%E3%83%BC%E3%83%A1%E3%83%B3/>