<https://www.themarker.com/magazine/2015-06-18/ty-article/0000017f-f87c-d318-afff-fb7f2e390000>
<http://www.w3.org/1999/02/22-rdf-syntax-ns#type>
<https://www.themarker.com/magazine/2015-06-18/ty-article/0000017f-f87c-d318-afff-fb7f2e390000>