T, B., and U. K. “Effect of a comprehensive heart failure treatment program on left ventricular ejection fraction and six-minute walk distance in heart failure patients with reduced ejection fraction at Lampang Hospital”. Biomedical Sciences and Clinical Medicine, vol. 59, no. 1, Jan. 2020, pp. 1-9, https://he01.tci-thaijo.org/index.php/CMMJ-MedCMJ/article/view/183019.