<https://style.nikkei.com/article/DGXZQOFK091RZ0Z00C22A8000000?channel=ASH02002&k=202107180300>
<http://www.w3.org/1999/02/22-rdf-syntax-ns#type>
<https://style.nikkei.com/article/DGXZQOFK091RZ0Z00C22A8000000?k=202107180300>