S. N. Abdulmadjid, K. H. Kurniawan, T. J. Lie, Y. I. Lee, I. Kitazima, and K. Kagawa, “Low-Cost Real-Time Gas Monitoring Using a Laser Plasma Induced by a Third Harmonic Q-Switched Nd-YAG Laser”, J. Eng. Technol. Sci., vol. 37, no. 2, pp. 91-106, Jan. 2014.