Lakshmi Paruchuri, Vijaya, and Dr P. Rajesh. “IoT for Monitoring Carbon Monoxide (CO) Emissions Using Wireless Sensor Networks in Smart Cities”. International Journal of Engineering & Technology, vol. 7, no. 2.7, Mar. 2018, pp. 1045-50, https://doi.org/10.14419/ijet.v7i2.7.12226.