<https://tek-nakanoshima.com/%e5%85%ac%e7%ab%8b%e9%ab%98%e6%a0%a1%e5%80%8d%e7%8e%87%e7%99%ba%e8%a1%a8%ef%bc%81/>
<http://www.w3.org/1999/02/22-rdf-syntax-ns#type>
<https://tek-nakanoshima.com/%E5%85%AC%E7%AB%8B%E9%AB%98%E6%A0%A1%E5%80%8D%E7%8E%87%E7%99%BA%E8%A1%A8%EF%BC%81/>