et. al., N. S. T. . “Analysis of Quality Control to Reduce Defective Products for Dry Syrup Using Six-Sigma Method in PT XYZ”. Turkish Journal of Computer and Mathematics Education (TURCOMAT), vol. 12, no. 7, Apr. 2021, pp. 2776-87, https://turcomat.org/index.php/turkbilmat/article/view/3814.