A. Hasibuan, M. Asaad, O. Krianto Sulaiman, A. Haris Nasution, M. Nasution, and L. Andriany, “Determination of Combination of Optimal Factor Level in Improvement and Uniform Effort of Product Quality Using Taguchi Method”, IJET, vol. 7, no. 2.14, pp. 301–304, Apr. 2018, doi: 10.14419/ijet.v7i2.12.14696.