S, P. “Relationship between 6-minute Walk Distance and Risk of Hospitalization from Exacerbation of COPD in One Year at Trang Hospital”. ASEAN Journal of Rehabilitation Medicine, vol. 29, no. 3, Dec. 2019, pp. 94-98, https://he01.tci-thaijo.org/index.php/aseanjrm/article/view/206687.