Mohammed, A.-H. A.-K., Hassan, R. H., & Hassan, K. H. (2003). Catalytic Pour Point Reduction and Viscosity Improvement of Lubricating Oil Fractions using Sulfided Nickel-Tungsten Catalysts. Iraqi Journal of Chemical and Petroleum Engineering, 4(1), 41-46. https://doi.org/10.31699/IJCPE.2003.1.6