Lechman, Ewa. “Catching-up and Club Convergence From Cross-National Perspective a Statistical Study for the Period 1980?201”. Equilibrium. Quarterly Journal of Economics and Economic Policy 7, no. 3 (September 30, 2012): 95–109. Accessed July 24, 2024. https://journals.economic-research.pl/eq/article/view/372.