Abdul-Karim Mohammed, A.-H. and Shehab Al – Rubai, A.K. 2008. Viscosity Index Improvement of Lubricating Oil Fraction (SAE – 30). Iraqi Journal of Chemical and Petroleum Engineering. 9, 3 (Sep. 2008), 51–57. DOI:https://doi.org/10.31699/IJCPE.2008.3.8.