Agus Alim, et al. “Development of a Smart Air Pollution Detection System Utilizing MQ2 Sensor and Node MCU ESP8266 With Telegram Integration”. Jurnal Ekonomi Manajemen Sistem Informasi, vol. 6, no. 3, Feb. 2025, pp. 1634-40, doi:10.38035/jemsi.v6i3.4075.