Unpikul, Boonkit, and Benjamas Dhinnabutra. 2026. “Application of Lean Office and Process Engineering to Improve the Productivity of a Labor Skills Certificate Management System: A Case Study of a National Labor Skills Testing Center”. Journal of Manufacturing & Management Technology 5 (1):19-33. https://ph01.tci-thaijo.org/index.php/jMMT/article/view/267293.