Kanchanathaweekul, Thawatchai, and Pratoom Muangmee. 2008. “Effects of Endurance Training and Breath-holding Training on Breath-holding Time, Maximal Oxygen Uptake, Lung Capacity, Red Blood Cell and White Blood Cell Counts”. Journal of Exercise and Sport Science 5 (1). Chonburi, Thailand:1-16. https://he01.tci-thaijo.org/index.php/buuss/article/view/86724.