<https://style.nikkei.com/article/DGXMZO75685820T10C21A9000000?channel=ASH09002&page=3>
<http://www.w3.org/1999/02/22-rdf-syntax-ns#type>
<https://style.nikkei.com/article/DGXMZO75685820T10C21A9000000?channel=DF030920184324&page=3>