M.Jawahar, Ch.Sridhar Reddy, Ch.Srinivas. “Multi-Quality Characteristics Optimization of NPMEDM of Nimonic 90 by Using Data Envelopment Analysis Based Ranking Technique”. Design Engineering, Nov. 2021, pp. 14541 -52, http://thedesignengineering.com/index.php/DE/article/view/6582.