Muzna Hameed Dar, Alam, S. M. ., Bukhari, Q. ul A. ., Ismail, K. ., & Zaidi, S. A. H. . (2021). Low Dose Theophylline and Tiotropium Rotacap as Add on Therapy in COPD Patients-Clinical Trial. Journal of Bahria University Medical and Dental College, 10(2), 137–141. https://doi.org/10.51985/JBUMDC2020001