<https://lowch.com/archives/tag/%E8%B5%A4%E3%83%AF%E3%82%A4%E3%83%B3/#collectionpage>
<http://www.w3.org/1999/02/22-rdf-syntax-ns#type>
<https://lowch.com/archives/tag/%E8%B5%A4%E3%83%AF%E3%82%A4%E3%83%B3>