https://www.ecb.europa.eu/pub/pdf/ecbu/eb201703.en.pdf?ea7747ab0ef3b038300a8d51a3a95313
https://www.riksbank.se/en-gb/press-and-published/notices-and-press-releases/debate-articles/payments-in-the-future-and-legal-protection-for-the-swedish-krona/
https://www.sciencedirect.com/science/article/pii/S0022199617301411
https://www.huffingtonpost.co.uk/entry/test-and-trace-spending-ps37bn-budget-small-print_uk_60412920c5b601179ec35d4a