Boonla, Orachorn, Piyapong Prasertsri, Utit Rungsawat, Sikarin Namkhum, Bhornluck PaepetchSuato, and Nongnuch Luangpon. 2017. “An Eight-Week of Inspiratory Muscle Training Program Improved Chest Expansion in Subjects With Inspiratory Muscle Weakness: A Preliminary Study”. Srinagarind Medical Journal 32 (4):120-26. https://li01.tci-thaijo.org/index.php/SRIMEDJ/article/view/94349.