1. The Evolution of Currency: Cash to Cryptos to Sovereign Digital Currencies;See Anton;FORDHAM INTERNATIONAL LAW JOURNAL,2019
2. Report of the Euro Legal Tender Expert Group (ELTEG) on the Definition, Scope and Effects of Legal Tender of Euro Banknotes and Coins;and the corresponding European Commission Recommendation of March 22, 2010 on the Scope and Effects of Legal Tender of Euro Banknotes and Coins,2010