Dr. Rajendra Kumar, Dr. Amrendra Kumar*. 2020. “A Randomized Controlled Trial to Compare the Efficacy and Safety of Glycopyrronium Bromide + salmeterol/fluticasone and Tiotropium Bromide + salmeterol/Fluticasone in Chronic Obstructive Pulmonary Disease”. Innovative Journal of Medical and Health Sciences 10 (05):853-57. https://innovativejournal.in/index.php/ijmhs/article/view/2917.