Hamdan, Rafidah, and Duncan Mara. “Aerated Blast-Furnace-Slag Filters for the Simultaneous Removal of Nitrogen and Phosphorus from Primary Facultative Pond Effluents”. International Journal of Integrated Engineering 5, no. 1 (November 20, 2013). Accessed November 26, 2020. https://publisher.uthm.edu.my/ojs/index.php/ijie/article/view/769.