1. SPAN (2019) SPAN annual report 2018. Accessed online through https://www.span.gov.my/document/upload/D5JoapftrLSaCCPh69zqhGokD8pzvN8B.pdf
2. SSD (2020) Details of sewerage system in Sarawak as at 31 December 2018. Accessed online through https://ssd.sarawak.gov.my/upload/file_folder/Data%20&%20Statistics/Inventory%20Wastewater%20Treatment%20Facilities/Summary%20of%20IWTF%20as%20at%2031.12.2018.pdf
3. Cisneros BJ (2011) Safe sanitation in low economic development areas. Treatise Water Sci 2011:147–200
4. Dahiya A (2020) Biofuel conversion pathways service learning projects and case studies. In: Bioenergy. Academic Press, Cambridge, MA, pp 671–690
5. El-Hafiz AA, Farghaly SM, El Baz AR (2017) Study the performance of circular clarifier in existing potable water treatment plant by using computational fluid dynamics. XVI World Water Congress. International Water Resources Association, Mexico