https://www.ecb.europa.eu/press/key/date/2012/html/sp120726.en.html
https://securingdemocracy.gmfus.org/wp-content/uploads/2020/08/ASD-Covert-Foreign-Money.pdf
https://www.brookings.edu/wp-content/uploads/2018/04/es_20180416_digitalcurrencies.pdf
https://www.boeckler.de/pdf/p_imk_study_58_2018.pdf