Vitomskyi, Volodymyr, Khaled Al-Hawamdeh, Lazarіeva Оlena, and Vitomskа Maryna. “The Efficacy of Using Tri-Ball Breathing Exerciser in Respiratory Function Recovery of the Patients Undergoing Cardiac Surgery”. Journal of Human Sport and Exercise 17, no. 2 (April 1, 2022): 341–350. Accessed April 25, 2024. https://www.jhse.ua.es/article/view/2022-v17-n2-efficacy-tri-ball-breathing-exerciser-respiratory-fu.