
https://openknowledge.worldbank.org/bitstream/handle/10986/36647/What-Has-Been-the-Impact-of-COVID-19-on-Debt-Turning-a-Wave-into-a-Tsunami.pdf?sequence=1&isAllowed=y

https://www.eurofound.europa.eu/sites/default/files/ef_publication/field_ef_document/fomeef18002en.pdf

http://wir2018.wid.world/files/download/wir2018-summary-german.pdf