<https://www.jlptmatome.com/%e8%81%9e%e3%81%8d%e5%8f%96%e3%82%8b-vocabulary-meaning/>
<http://www.w3.org/1999/02/22-rdf-syntax-ns#type>
<https://www.jlptmatome.com/%E8%81%9E%E3%81%8D%E5%8F%96%E3%82%8B-vocabulary-meaning/>