P. A. Khan, A. Sujala, B. B. S. Nousheen, A. F. Fatima, H. T. Ala, and A. B. T. P. Reddy, “A COMPARATIVE EVALUATION OF THE EFFICACY OF TRIPLE DRUG THERAPY WITH DUAL DRUG THERAPY IN COPD PATIENTS”, Int J Pharm Pharm Sci, vol. 10, no. 4, pp. 105–109, Apr. 2018.