M. Hashim, W. R. Ismail, M. S. Y. Che Ngah, N. Nayan, Y. Saleh, and Z. M. Said, “Trend Luahan Tahunan di LembanganSungai Perak 1915-2006: Sungai Perak’s Catchment Yearly Discharge Trend 1915-2006”, PERS, vol. 3, no. 2, pp. 53–63, Nov. 2011, Accessed: Dec. 15, 2025. [Online]. Available: https://ejournal.upsi.edu.my/index.php/PERS/article/view/1599