<https://www.isaburou.com/post/\u30D3\u30C3\u30AF\u30B5\u30A4\u30BA\uFF01\u3048\u3073\u30D5\u30E9\u30A4>
<http://www.w3.org/1999/02/22-rdf-syntax-ns#type>
<https://www.isaburou.com/post/%E3%83%93%E3%83%83%E3%82%AF%E3%82%B5%E3%82%A4%E3%82%BA%EF%BC%81%E3%81%88%E3%81%B3%E3%83%95%E3%83%A9%E3%82%A4>