AL-RABASI DAM, ALI DFAM, ABDEL RAZZAQ DA, ABDO DRM. X-bar Chart Based on Six Sigma to Continual Quality Improvement: Implementation on Oil Vapor Pressure Characteristic, at Yemen’s Aden Oil Refinery. hesj [انترنت]. 27 سبتمبر، 2022 [وثق 23 سبتمبر، 2026];(25):671-99. موجود في: http://hesj.org/ojs/index.php/hesj/article/view/549