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 and Technology, vol. 7, no. 2.7, Mar. 2018, pp. 1045-50, https://doi.org/10.14419/ijet.v7i2.7.12226.