Boonchuduang, S., W. Juthasantikul, A. Chantarokorn, and W. Wasinwong. “Effects of Using Video Guided about Deep-Breathing Exercise for Patient Preparation before Receiving General Anesthesia”. Srinagarind Medical Journal, vol. 27, no. 2, Aug. 2013, pp. 139-46, https://li01.tci-thaijo.org/index.php/SRIMEDJ/article/view/11102.