Afrizal, Arif, and Gatot Yudoko. “Proposed Improvement of Diesel and Jet Fuel Planning Management at PT. OGC Using Six Sigma DMAIC”. Eduvest - Journal of Universal Studies 6, no. 6 (June 22, 2026): 7310–7322. Accessed October 7, 2026. http://www.eduvest.greenvest.co.id.submitjurnal.id/index.php/edv/article/view/52895.