Vasuthada, Cuttaliya. 2018. “The Operational System Improvement for Service Time Reduction of Patients with Chronic Diseases, Thachang Primary Care Unit, Chanthaburi Province”. Journal of Phrapokklao Nursing College, Chanthaburi 28 (1). Chanthaburi, Thailand:80-89. https://he01.tci-thaijo.org/index.php/pnc/article/view/117872.