<https://keiko-onuki.com/2018/06/13/%e6%90%8d%e3%82%92%e3%81%97%e3%81%a6%e3%82%82%e8%89%af%e3%81%84%e3%81%a8%e6%80%9d%e3%81%88%e3%82%8b%e3%81%8b/#breadcrumblist>
<http://www.w3.org/1999/02/22-rdf-syntax-ns#type>
<https://keiko-onuki.com/2018/06/13/%E6%90%8D%E3%82%92%E3%81%97%E3%81%A6%E3%82%82%E8%89%AF%E3%81%84%E3%81%A8%E6%80%9D%E3%81%88%E3%82%8B%E3%81%8B/>