Ibrahim, Gusri Akhyar, Arinal Hamni, and Sri Maria Puji Lestari. 2019. “Analysis of Surface Roughness Value When Drilling Magnesiumaz31 Using Taghuci Method”. International Series on Interdisciplinary Science and Technology 2 (2):71-74. https://doi.org/10.23960/ins.v2i2.82.