“Rivers and Lakes as Natural Heritage: Water Quality Status in the Northern States of Peninsular Malaysia”, KAJH, vol. 23, no. Supp. 1, pp. 109–128, May 2016, Accessed: Dec. 23, 2024. [Online]. Available: https://ejournal.usm.my/kajh/article/view/kajh_vol23-s1-2016_6