Mohammed, A.-H.A.-K., Hassan, R.H. and 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), pp. 41–46. doi:10.31699/IJCPE.2003.1.6.