Abdul Rahim, L., M. Hashim, M. S. Y. Che Ngah, N. Nayan, and Y. Saleh. “Kualiti Air Tirisan: Kajian Kes Di Ulu Yam Dan Kuala Kubu Bharu, Selangor: Seepage Water Quality: A Case Study in Ulu Yam and Kuala Kubu Bharu, Selangor”. GEOGRAFI, vol. 2, no. 1, Dec. 2018, pp. 86-97, https://ojs.upsi.edu.my/index.php/GEOG/article/view/470.