Salim, M. R., M. H. Ibrahim, A. I. Azmi, M. Y. Mohd Noor, A. S. Abdullah, N. H. Ngajikin, H. Manap, G. Dooly, and E. Lewis. “Highly Responsive CO2 Detection by an Improved &Amp; Compact Gas Sensor Using Mid-IR Spectroscopy”. Journal of Telecommunication, Electronic and Computer Engineering (JTEC), vol. 10, no. 2-8, July 2018, pp. 1-7, https://jtec.utem.edu.my/jtec/article/view/4449.