Hamdan, R., Nur Amira Atierah Mohammed Shaikhani, and Nur Ain Nazirah Mohd Arshad. “Aerobic-Anoxic Filter For Nitrogen Removal From Domestic Wastewater: A Comparison Study”. Recent Trends in Civil Engineering and Built Environment, vol. 1, no. 1, Dec. 2020, pp. 133-41, https://publisher.uthm.edu.my/periodicals/index.php/rtcebe/article/view/237.