Shringi S, Mishra MK, Singh AK. To study 6MWT as a prognostic marker in stable COPD patients & its correlation with spirometry grading. Pak J Chest Med [Internet]. 2021Jan.10 [cited 2026Sep.16];26(4):187-93. Available from: https://www.pjcm.net/index.php/pjcm/article/view/670