Che Harun, Mohammad Hakim, et al. “Rapid-Slow Sand Filtration for Groundwater Treatment: Effect of Filtration Velocity and Initial Head Loss”. International Journal of Integrated Engineering, vol. 14, no. 1, Mar. 2022, pp. 276-8, https://publisher.uthm.edu.my/ojs/index.php/ijie/article/view/6683.