<https://sakura.photogenic2000.com/archives/item/%e3%83%8f%e3%83%bc%e3%83%95%e6%88%90%e4%ba%ba%e5%bc%8f%e7%94%b7%e5%85%90#webpage>
<http://www.w3.org/1999/02/22-rdf-syntax-ns#type>
<https://sakura.photogenic2000.com/archives/item/%E3%83%8F%E3%83%BC%E3%83%95%E6%88%90%E4%BA%BA%E5%BC%8F%E7%94%B7%E5%85%90>