“Correlation Between Level of Physical Activity Using IPAQ and Exercise Capacity Using 6 Min Walk Test in COPD Patients. A Cross Sectional Study”. International Journal of Biomedical and Advance Research 11, no. 5 (May 30, 2020): e5425. Accessed May 3, 2026. https://www.ssjournals.co.in/index.php/ijbar/article/view/5425.