5Rogoff, Kenneth. (1996). "The Purchasing Power Puzzle," Journal of Economic Literature, 34:2, pp. 647-668.
6Wincenciak, Leszek (2005) : "Balassa-Samuelson effect in Poland during the transition: Real versus nominal convergence",Working Paper, Macroeconomics and Trade Theory Division, Faculty of Economics, Warsaw University, Nov. 17, 2005.
10Balassa, Bela (1964), "The Purchasing-Power Parity Doctrine: A Reappraisal", The Journal of Political Economy, Vol.72, No. 6(Dec., 1964), pp. 584-596.