Bhangam, C. “The Relation Between Intra – Organizational Communication and personnel’s Operational Efficiency of Office of the President, Mahidol University”. NKRAFA Journal of Humanities and Social Sciences, vol. 10, Dec. 2022, pp. 33-44, https://so04.tci-thaijo.org/index.php/KANNICHA/article/view/256077.