<https://about.bloomberg.co.jp/blog/researching-supply-chain-exposures-how-to-analyse-coronavirus-related-risks/#webpage>
<http://www.w3.org/1999/02/22-rdf-syntax-ns#type>
<https://about.bloomberg.co.jp/blog/researching-supply-chain-exposures-how-to-analyse-coronavirus-related-risks/>