Abd Aziz, Nor Izzah. “Optimization of PH and Contact Time of Media in Removing Calcium and Magnesium from Groundwater”. International Journal of Integrated Engineering 11, no. 9 (December 30, 2019): 063–072. Accessed May 19, 2024. https://penerbit.uthm.edu.my/ojs/index.php/ijie/article/view/5429.