Hia, Selamat W., and Moses Laksono Singgih. “Improving Tire Lifespan Using the Six Sigma Approach: A Case Study in a Coal-Hauling Company”. Management and Production Engineering Review 16, no. 1 (March 30, 2025): [nr art. 11], s. 1–7. Accessed September 20, 2026. https://wydawnictwo.pan.pl/index.php/mper/article/view/5622.