<https://yuuga-official.com/%e8%87%aa%e5%88%86%e3%82%92%e6%95%b4%e3%81%88%e3%82%8b%e6%97%a5/>
<http://www.w3.org/1999/02/22-rdf-syntax-ns#type>
<https://yuuga-official.com/%E8%87%AA%E5%88%86%E3%82%92%E6%95%B4%E3%81%88%E3%82%8B%E6%97%A5/>