Jansang, Sarawut, Parunkul Tungsukruthai, Sorachai Srisuma, Kusuma Sriyakul, Aungkana Krajarng, and Somboon Kietinun. 2021. “Effect of Pursed-Lip Breathing Using a Windmill Toy Model on Breathing Efficiency in Chronic Obstructive Pulmonary Disease Patients”. Trends in Sciences 18 (23). Nakhon Si Thammarat, Thailand:714. https://doi.org/10.48048/tis.2021.714.