<https://go2senkyo.com/articles/tag/%e3%82%ab%e3%82%b9%e3%83%88%e3%83%ad#webpage>
<http://www.w3.org/1999/02/22-rdf-syntax-ns#type>
<https://go2senkyo.com/articles/tag/%E3%82%AB%E3%82%B9%E3%83%88%E3%83%AD>