Anusak, K., . R. Matanasarawoot, P. . Sakarinkhul, and W. Jiraporncharoen. “Factors Affecting an Acute Exacerbation Among COPD Patients in the Emergency Room, Lamphun Hospital”. Journal of The Department of Medical Services, vol. 46, no. 4, Jan. 2022, pp. 67-73, https://he02.tci-thaijo.org/index.php/JDMS/article/view/251477.