Suarin, N.A.S., Chia, K.S. and Mohamad Fuzi, S.F.Z. (2018) “A Portable in-situ Near-infrared LEDs-based Soil Nitrogen Sensor”, International Journal of Integrated Engineering, 10(4). Available at: https://penerbit.uthm.edu.my/ojs/index.php/ijie/article/view/2316 (Accessed: 7 April 2026).