<https://kiyosato-shochu.com/blogs/%E3%83%8B%E3%83%A5%E3%83%BC%E3%82%B9/%E4%BB%8A%E5%B9%B4%E3%82%82%E9%85%92%E9%80%A0%E3%82%8A%E3%81%8C%E5%A7%8B%E3%81%BE%E3%82%8A%E3%81%BE%E3%81%97%E3%81%9F>
<http://www.w3.org/1999/02/22-rdf-syntax-ns#type>
<https://kiyosato-shochu.com/blogs/%E3%83%8B%E3%83%A5%E3%83%BC%E3%82%B9/%E4%BB%8A%E5%B9%B4%E3%82%82%E9%85%92%E9%80%A0%E3%82%8A%E3%81%8C%E5%A7%8B%E3%81%BE%E3%82%8A%E3%81%BE%E3%81%97%E3%81%9F>