<https://www.avdlog.com/%e3%83%ac%e3%83%b3%e3%83%80%e3%83%bc%e3%82%a8%e3%83%ac%e3%83%a1%e3%83%b3%e3%83%88%e3%81%a8%e3%81%af-%e6%a6%82%e8%a6%81%e7%b7%a8/>
<http://www.w3.org/1999/02/22-rdf-syntax-ns#type>
<https://www.avdlog.com/tag/%E3%83%AC%E3%83%B3%E3%83%80%E3%83%BC%E3%82%A8%E3%83%AC%E3%83%A1%E3%83%B3%E3%83%88/>