A. Sunar, B. Lamichhane, G. Pandey, J. Yogi, and N. Poudel, “Trek Monitoring System: Enhancing Safety and Adventure in the Outdoors using Arduino UNO and NodeMCU”, JEI, vol. 5, no. 3, pp. 235–252, Aug. 2023, doi: 10.36548/jei.2023.3.001.