“Effect Of Acapella Versus Lung Flute On Pulmonary Function, Exercise Capacity, And Quality Of Life In Chronic Obstructive Pulmonary Disease Patients: A Randomised Clinical Trial”. International Journal of Environmental Sciences (September 8, 2025): 1241–1253. Accessed September 11, 2025. https://theaspd.com/index.php/ijes/article/view/9184.