<https://happy-dreamer.com/%e5%9b%9e%e8%bb%a2%e3%81%97%e3%81%a6%e3%81%aa%e3%81%84%e3%81%8a%e5%af%bf%e5%8f%b8/>
<http://www.w3.org/1999/02/22-rdf-syntax-ns#type>
<https://happy-dreamer.com/%E5%9B%9E%E8%BB%A2%E3%81%97%E3%81%A6%E3%81%AA%E3%81%84%E3%81%8A%E5%AF%BF%E5%8F%B8/>