<http://yuitotaguchi.com/2018/07/13/%e7%ab%b6%e4%ba%89%e3%81%a3%e3%81%a6%e6%9c%80%e6%82%aa%e3%81%a0%e3%81%a8%e6%80%9d%e3%81%86/>
<http://www.w3.org/1999/02/22-rdf-syntax-ns#type>
<http://yuitotaguchi.com/2018/07/13/%E7%AB%B6%E4%BA%89%E3%81%A3%E3%81%A6%E6%9C%80%E6%82%AA%E3%81%A0%E3%81%A8%E6%80%9D%E3%81%86/>