Abolfazl Semnani. “Application Of Icp-Oes In The Comparative Analysis Of A Used And Fresh Gasoline Motor Oil”. Global Journal of Science Frontier Research 12, no. B2 (January 15, 2012): 9–14. Accessed April 30, 2024. https://journalofscience.org/index.php/GJSFR/article/view/412.