1. Coughlin, C. C. and T. B. Mandelbaum: 1988, ‘Why have state per capita incomes diverged recently?’, Review of the Federal Reserve Bank of St. Louis 70, pp. 24–36.
2. Abdel-Ghany, M.: 1991, ‘Income inequality within the U.S.A.: with emphasis on the “South”’, Journal of Consumer Studies and Home Economics 15, pp. 339–345.
3. Abdel-Ghany, M.: 1996, ‘Demographic and economic determinants of household income polarization among the states of America’, Family Economics and Nutrition Review 9, pp. 14–23.
4. Al-Sammarie, A. and H. P. Miller: 1967, ‘State differentials in income concentration’, American Economic Review 57, pp. 59–72.
5. Aigner, D. J. and A. J. Heinz: 1967, ‘On the determination of income inequality’, American Economic Review 57, pp. 175–184.