See, Koh Liew, Hamirdin Ithnin, and Mohamad Suhaily Yusri Che Ngah. 2015. “Kajian Perbandingan Antara Realiti Dengan Persepsi Mengenai Kualiti Bekalan Air Di Kelantan: Comparison Between Reality and Perception of Water Supply Quality in Kelantan”. GEOGRAFI 3 (1):35-47. https://ojs.upsi.edu.my/index.php/GEOG/article/view/1846.