Tariq, Muhammad Usman, and M. Naeem Ahmed Khan. “An Insight into Risk Identification, Quality and Productivity Enhancement Using Six Sigma”. Journal of Education and Vocational Research 2, no. 1 (July 15, 2011): 24–33. Accessed October 25, 2026. https://amhinternational.com/jevr/article/view/4357-an-insight-into-risk-identification-quality-and-productivity-enhancement-using-six-sigma.