Boonla, O., P. Prasertsri, and A. Srithawong. “Inspiratory muscle training improves thoracic expansion and six-minute walking distance in female subjects with inspiratory muscle weakness”. Journal of Physiological and Biomedical Sciences, vol. 32, no. 1, Mar. 2020, pp. 5-10, https://li01.tci-thaijo.org/index.php/j-pbs/article/view/250665.