Ramli, Suzana, Aminuddin Mohd Baki, Muhamad Azmi Ayub, Suhaimi Abdul Talib, Ramlah Mohd Tajuddin, Ismail Atan, Jurina Jaafar, and Nur Aziafwani Abdullah. 2008. “Renewable Energy from Biogas Generated by Sewage Sludge – Relationship Between Sludge Volume and Power Generated”. Scientific Research Journal 5 (2):1-9. https://doi.org/10.24191/srj.v5i2.5641.