<https://yoshikei-plus-one.com/2019/12/30/12%e6%9c%8828%e6%97%a5%ef%bc%88%e6%97%a5%ef%bc%89%e3%81%ae%e9%a3%9f%e5%8d%93%e3%81%8b%e3%82%89/>
<http://www.w3.org/1999/02/22-rdf-syntax-ns#type>
<https://yoshikei-plus-one.com/2019/12/30/12%E6%9C%8828%E6%97%A5%EF%BC%88%E6%97%A5%EF%BC%89%E3%81%AE%E9%A3%9F%E5%8D%93%E3%81%8B%E3%82%89/>