<https://izumiotsu-rc.org/2019/12/20/#listItem>
<http://www.w3.org/1999/02/22-rdf-syntax-ns#type>
<https://izumiotsu-rc.org/2019/12/20/%E3%82%AF%E3%83%AA%E3%82%B9%E3%83%9E%E3%82%B9%E4%BE%8B%E4%BC%9A-2/>