S. D. Seo, H.- jong Paik, S. Lee, K. Kang, and J. D. Lee, “Investigation on the Synergistic Effect of Tetra Butyl Phosphonium Bromide with Poly(N-isopropylacrylamide) Based Kinetic Hydrate Inhibitor”, Chemical Engineering Transactions, vol. 78, pp. 175-180, Feb. 2020.