Z Radzi, E, M. S Wahab, M Z Sahdan, R Hamdan, and A A Raus. 2019. “The Effects of Using Stepped Cascade Aeration and Multimedia Filter System for Iron Removal in Groundwater”. International Journal of Engineering & Technology 8 (1.1): 201-6. https://doi.org/10.14419/ijet.v8i1.1.24660.