R. Rawi, M. S. Iman Hasnan, and A. Abu Bakar Sajak, “Palm Oil Soil Monitoring System for Smart Agriculture”, IJIE, vol. 12, no. 6, pp. 189–199, Jul. 2020, Accessed: Aug. 07, 2026. [Online]. Available: https://journal.uthm.edu.my/index.php/ijie/article/view/6604