<https://www.umedasekkotuin.com/3%e6%9c%88%e3%81%ae%e8%a8%ba%e7%99%82%e3%81%ab%e3%81%a4%e3%81%84%e3%81%a6-3/#article>
<http://www.w3.org/1999/02/22-rdf-syntax-ns#type>
<https://www.umedasekkotuin.com/3%E6%9C%88%E3%81%AE%E8%A8%BA%E7%99%82%E3%81%AB%E3%81%A4%E3%81%84%E3%81%A6-3/>