<https://mazasse.com/2017/02/24/3%e6%9c%8811%e6%97%a5%ef%bc%88%e5%9c%9f%ef%bc%89%e2%97%86%e7%a6%8f%e9%ad%82%e7%a5%ad/>
<http://www.w3.org/1999/02/22-rdf-syntax-ns#type>
<https://mazasse.com/2017/02/24/3%E6%9C%8811%E6%97%A5%EF%BC%88%E5%9C%9F%EF%BC%89%E2%97%86%E7%A6%8F%E9%AD%82%E7%A5%AD/>