Agarwal, Arun, Kishan Ray, Biplab Kumar Pradhan, and Vishaka Kumari. “GSM Based Smart Digital Wireless Electronic Notice Board”. Journal of Information Technology and Digital World 4, no. 3 (August 8, 2022): 144–152. Accessed September 15, 2026. https://irojournals.com/itdw/article/view/1341.