Mahmoud, Hoda Esmat, Soheir Bader EL-Din, Mona Sadek, and Labiba Abd-El kader. 2017. “Efficacy of Breathing Exercises on Daily Living Activities of Patients With Chronic Obstructive Pulmonary Disease”. International Journal of Nursing Didactics 7 (6):44-53. https://doi.org/10.15520/ijnd.2017.vol7.iss6.225.