Ray SC (1999). “Measuring Scale Efficiency from a Translog Production Function.” JPA 11(2): 183-194.

Ray SC (2004). Data Envelopment Analysis: Theory and Techniques for Economics and Operations Research. Cambridge, UK, Cambridge University Press.

Ray SC and E Desli (1997). “Productivity Growth, Technical Progress, and Efficiency Change in Industrialized Countries: Comment.” American Economic Review 87(5): 1033-1039.

Ray SC and K Hiung Joon (1995). “Cost Efficiency in the US Steel Industry: A Nonparametric Analysis Using Data Envelopment Analysis.” EJOR 80: 654-671.

Ray SC and XW Hu (1997). “On the Technically Efficient Organization of an Industry: A Study of US Airlines.” JPA 8(1): 5-18.

Ray SC and HJ Kim (1995). “Cost Efficiency in the United-States Steel-Industry – a Nonparametric Analysis Using Data Envelopment Analysis.” EJOR 8: 654-671.

Ray SC and K Mukherjee (1996). “Decomposition of the Fisher Ideal Index of Productivity: A Non-Parametric Dual Analysis of US Airlines Data.” Economic Journal 106(439): 1659-1678.

Rangan N, R Grabowski, HY Aly and C Pasurka (1988). “The Technical Efficiency of US Banks.” Economics Letters 2: 169-175.

Rao R (1992). “Efficiency and Equity in Dynamic Principal-Agent Problems.” J Economics 5: 17-41.

Rassafi AA and M Vaziri (2005). “Application of Data Envelopment Analysis in Identifying Milestones for Passenger and Freight Transportation Sustainability.” Scientia Iranica 12(4): 426-436.