A. . Yankai, J. . Leelarungrayub, R. . Kanthain, and J. J. . Laskin, “Preliminary Study: Immediate Effect of the Slow Deep Breathing Exercise and Sustained Maximal Inspiration with Volume-Oriented Incentive Spirometry on the Diffusing Lung Capacity in Healthy Young Participants”, Trends Sci, vol. 18, no. 21, p. 346, Oct. 2021.