<http://emacoffee.com/2011/07/01/%e4%bb%8a%e6%97%a5%e3%81%8b%e3%82%89%e3%82%b5%e3%83%9e%e3%83%bc%e3%82%bf%e3%82%a4%e3%83%a0%e5%b0%8e%e5%85%a5%ef%bc%81/#listItem>
<http://www.w3.org/1999/02/22-rdf-syntax-ns#type>
<http://emacoffee.com/2011/07/01/%E4%BB%8A%E6%97%A5%E3%81%8B%E3%82%89%E3%82%B5%E3%83%9E%E3%83%BC%E3%82%BF%E3%82%A4%E3%83%A0%E5%B0%8E%E5%85%A5%EF%BC%81/>