A Study of Parameters Affecting the Solvent Extraction-Flocculation Process of Used Lubricating Oil. Journal of Engineering, [S. l.], v. 23, n. 6, p. 63–73, 2017. DOI: 10.31026/j.eng.2017.06.05. Disponível em: https://joe.uobaghdad.edu.iq/index.php/main/article/view/33. Acesso em: 14 mar. 2025.