Kaju, S., P. Yonglitthipagon, W. Donpunha, and S. Bennett. “Comparison of Crackle Characteristics in the Lungs Between Mild and Moderate Smokers Using CALSA: A Pilot Study”. Archives of Allied Health Sciences, vol. 30, no. 1, June 2018, pp. 93-107, https://he01.tci-thaijo.org/index.php/ams/article/view/126656.