Guduri Srikanth, Yerroju Praveen, Bharatha Preetham, Maddini Avinash Kumar, M. Anusha, P. S. G. Aruna Sri. “Implementation of a Cluster Based Letter Box System Using IOT”. International Journal of Advanced Science and Technology 29, no. 3 (March 30, 2020): 11082 - 11087. Accessed July 23, 2024. https://sersc.org/journals/index.php/IJAST/article/view/28003.