Nagawaram, Panduranga Rao, and Vashishta Kanchanpally. 2016. “Comparative Study of Theophylline and Doxofylline in the Treatment of Stable Chronic Obstructive Pulmonary Disease”. International Journal of Basic & Clinical Pharmacology 5 (2):251-56. https://doi.org/10.18203/2319-2003.ijbcp20160464.