<https://style.nikkei.com/article/DGXMZO71261610S1A420C2000000?channel=ASH01006>
<http://www.w3.org/1999/02/22-rdf-syntax-ns#type>
<https://style.nikkei.com/article/DGXMZO71261610S1A420C2000000?channel=DF090220166680>