1. Acemoglu D., Robinson J.A., Why nations fail: The origins of power, prosperity, and poverty (Crown Publishers, USA, 2012)
2. Baliazin V.N. (Ed.), Mudrost tysyacheletiy. Entsiklopediya [The wisdom of the millennia. Encyclopedia] (Olma-Press, Moscow, 2005)
3. Kovalchenko I.D., Metody istoricheskogo issledovaniya [Historical research methods] (Nauka, Moscow, 2003)
4. World Bank, GDP (current US$). World Bank national accounts data, and OECD National Accounts data files (n.d.). Accessed on: December 20, 2020. [Online]. Available: https://data.worldbank.org/indicator/NY.GDP.MKTP.CD
5. World Bank, GDP per capita, PPP (current international $). International comparison program, World Development Indicators database, Eurostat-OECD PPP Programme (n.d.). Accessed on: December 20, 2020. [Online]. Available: https://data.worldbank.org/indicator/NY.GDP.PCAP.PP.CD