1. M. Ayub , Income Inequality in a Growth-Theoretic Context: The Case of Pakistan , unpublished doctoral dissertation, Yale University, 1977 .
2. J. S. Cramer , "Efficient Grouping, Regression and Correlation in Engel Curve Analysis ," Journal of the American Statistical Association, March, 1964 .
3. T. S. Das, and A. Parikh , "Decomposition of Inequality Measures and a Comparative Analysis ," School of Social Studies, University of East Anglia, Discussion Paper No. 44, 1977 .