Kurnia Rapa, Menahim Fajar, and Noorhan Firdaus Pambudi. 2026. “Integrating Lean Six Sigma and Soil Quality Preservation in Topsoil Removal Operations: A Case Study of Indonesian Coal Mining”. Devotion : Journal of Research and Community Service 7 (8):1014-31. https://doi.org/10.59188/devotion.v7i8.25755.