1. Arestis, P., & Sawyer, M. C. (1994). The Elgar companion to radical political economy. Edward Elgar Publishing. Elgar. pp. 415–419. ISBN 1–85278–460–1. OCLC 28547509.
2. Baltagi, B. (2008). Econometric analysis of panel data. John Wiley & Sons.
3. Bassey Okon, E., & Felix Awara, E. (2018). Institutional quality and economic diversification in oil-rich economies: A case study of Nigeria. Journal of Economics and Sustainable Development, 19(14), 57–62.
4. Bayraktutan, Y., Bıdırdı, H., & Kutlar, A. (2018). Research and development and high technology exports in selected countries at different development stages: A panel co-integration and causality analysis German-Turkish Perspectives on IT and Innovation Management 43–72 https://doi.org/10.1007/978-3-658-16962-6_3
5. Becchetti, L., Bruni, L., & Zamagni, S. (2019). The Microeconomics of Wellbeing and Sustainability, Recasting the Economic Process. 1st Edition; 139–156.