Rosa, Arida Amalia, et al. “Sistem Pendeteksi Pencemaran Udara Portabel Menggunakan Sensor MQ-7 Dan MQ-135”. Ultima Computing : Jurnal Sistem Komputer, vol. 12, no. 1, July 2020, pp. 23-28, doi:10.31937/sk.v12i1.1611.