<https://da.dl.itc.u-tokyo.ac.jp/portal/assets/4c16a261-375e-484e-9647-2300587c5347>
<http://www.w3.org/1999/02/22-rdf-syntax-ns#type>
<https://da.dl.itc.u-tokyo.ac.jp/portal/assets/4c16a261-375e-484e-9647-2300587c5347>