<https://safety-house.com/%e3%81%82%e3%81%a3%e3%81%9f%e3%81%8b%e5%ba%8a%e6%9a%96%e6%88%bf%e3%82%ad%e3%83%a3%e3%83%b3%e3%83%9a%e3%83%bc%e3%83%b3%e2%9c%a8/blog/>
<http://www.w3.org/1999/02/22-rdf-syntax-ns#type>
<https://safety-house.com/%E3%81%82%E3%81%A3%E3%81%9F%E3%81%8B%E5%BA%8A%E6%9A%96%E6%88%BF%E3%82%AD%E3%83%A3%E3%83%B3%E3%83%9A%E3%83%BC%E3%83%B3%E2%9C%A8/blog/>