Mr. Vinayak Kurale, Dr. Archana D. Methe, Miss. Smruti Umesh Kurulkar, Dr. Gloria Naik. TO COMPARE THE EFFICACY OF BUTEYKO BREATHING EXERCISE AND 90/90 BALL & BALLON BREATHING EXERCISE IN PATIENTS WITH STAGE 1 AND STAGE 2 CHRONIC OBSTRUCTIVE PULMONARY DISEASE. J Popl Ther Clin Pharmacol. 2026;33(1):558-568. doi:10.53555/gt22qp49