<https://f-asfida.com/%e3%82%b0%e3%83%ab%e3%83%bc%e3%83%94%e3%83%b3%e3%82%b0%e4%b8%80%e8%a6%a7-8/#itempage>
<http://www.w3.org/1999/02/22-rdf-syntax-ns#type>
<https://f-asfida.com/%E3%82%B0%E3%83%AB%E3%83%BC%E3%83%94%E3%83%B3%E3%82%B0%E4%B8%80%E8%A6%A7-8/>