الكعبي ر. ع. Diesial Engine Oil Production 15W- 40 API CI-4. Journal of Petroleum Research and Studies, [S. l.], v. 11, n. 2, p. 17-35, 2021. DOI: 10.52716/jprs.v11i2.501. Disponível em: https://jprs.gov.iq/index.php/jprs/article/view/501. Acesso em: 24 apr. 2024.