<https://dictionary.goo.ne.jp/word/en/%E5%AD%A4%E7%AB%8B%E4%B8%BB%E7%BE%A9%E8%80%85/>
<http://www.w3.org/1999/02/22-rdf-syntax-ns#type>
<https://dictionary.goo.ne.jp/word/en/%E5%AD%A4%E7%AB%8B%E4%B8%BB%E7%BE%A9%E8%80%85/>