D. Coondoo, A. Majumder and R. Ray, “A Method of Calculating Regional Consumer Price Differentials with Illustrative Evidence from India,” Review of Income and Wealth, Vol. 50, No. 1, 2004, pp. 51-68.
 D. Jolliffe, G. Datt and M. Sharma, “Robust Poverty and Inequality Measurement in Egypt: Correcting for Spatial-Price Variation and Sample Design Effects,” Review of Development Economics, Vol. 8, No. 4, 2004, pp. 557- 572. doi:10.1111/j.1467-9361.2004.00252.x
 C. H. Gong and X. Meng, “Regional Price Differences in Urban China 1986-2001: Estimation and Implication,” IZA Discussion Papers, No. 3621, 2008.
 D. Jolliffe, “Poverty, Prices, and Place: How Sensitive Is the Spatial Distribution of Poverty to Cost of Living Adjustments?” Economic Inquiry, Vol. 44, No. 2, 2006, pp. 296-310. doi:10.1093/ei/cbj016
 R. Kosfeld and H. F. Eckey, “Market Access, Regional Price Level and Wage Disparities: The German Case,” MAGKS Papers on Economics, Philipps-Universitt Marburg, Marburg, 2008.
 V. K. Borooah, P. P. M. Gregor, P. M. M. Kee and G. E. Mulholland, “Cost-of-Living Differences between the Regions of the United Kingdom,” In: J. Hills, Ed., New Inequalities, the Changing Distribution of Income and Wealth in the United Kingdom, Cambridge University Press, Cambridge, 1996, pp. 103-133.
 Istat, “Le Differenze nel Livello dei Prezzi tra i Capo- luoghi delle Regioni Italiane per Alcune Tipologie di Beni,” Istat, Roma, 2008.
 L. Cannari and G. Iuzzolino, “Le Differenze nel Livello dei Prezzi al Consumo tra Nord e Sud,” Questioni di Economia e Finanza, Banca d’Italia, 2009.
 P. Siminski and P. Saunders, “Accounting for Housing Costs in Regional Income Comparisons,” Australasian Journal of Regional Studies, Vol. 10, No. 2, 2004, pp. 139-156.
 A. J. M. Hagenaars and M. A. Zaidi, “Poverty Statistics in the Late 1980s: Research Based on Micro-Data,” Office for Official Publications of the European Communities, Luxembourg, 1994.
 N. T. Longford, M. G. Pittau, R. Zelli and R. Massari, “Measures of Poverty and Inequality in the Countries and Regions of EU,” ECINEQ Working Papers 182, Society for the Study of Economic Inequality, 2010.
 M. S. Handcock and M. Morris, “Relative Distribution Methods in the Social Sciences,” Cambridge University Press, Cambridge, 1999.
 R. Massari, M. G. Pittau and R. Zelli, “A Dwindling Middle Class? Italian Evidence in the 2000s,” Journal of Economic Inequality, Vol. 7, No. 4, 2009, pp. 333-350.