<https://yoshikei-plus-one.com/2020/11/17/11%e6%9c%8817%e6%97%a5%e7%81%ab%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/2020/11/17/11%E6%9C%8817%E6%97%A5%E7%81%AB%E3%81%AE%E9%A3%9F%E5%8D%93%E3%81%8B%E3%82%89/>