Muhammad, Ros Fatihah, and Omar Alkouri. “Geospatial Information Systems for Karst: Morpho-Geological Study in Kinta Valley, Perak, Malaysia”. Malaysian Journal of Science 28, no. 3 (December 24, 2009): 329–338. Accessed January 6, 2025. http://borneojournal.um.edu.my/index.php/MJS/article/view/7641.