https://www.ussif.org/files/GSIR_Review2018F.pdf
https://iea.org.uk/wp-content/uploads/2023/12/Dowd-Free-Banking-Interactive.pdf
https://www.mckinsey.com/industries/financial-services/our-insights/how-payments-can-adjust-to-the-coronavirus-pandemic-and-help-the-world-adapt
http://www.imf.org/external/np/seminars/eng/2015/secularstag/pdf/Venkateswaran.pdf