Baidoo, F., and J. B. Servo. “Lean and Six Sigma Improvement Concept: Automobile After-Sales Service Delays on Customer Satisfaction in Ghana”. AFRICAN JOURNAL OF APPLIED RESEARCH 3, no. 1 (April 12, 2017): 121–134. Accessed November 21, 2024. https://ajaronline.com/index.php/AJAR/article/view/204.