<https://cts.m.u-tokyo.ac.jp/tag/%e5%a4%96%e7%a7%91%e8%aa%8d%e5%ae%9a%e5%8c%bb/#webpage>
<http://www.w3.org/1999/02/22-rdf-syntax-ns#type>
<https://cts.m.u-tokyo.ac.jp/tag/%E5%A4%96%E7%A7%91%E8%AA%8D%E5%AE%9A%E5%8C%BB/>