Chen R, Zhong N, Wang HY, Zhao L, Mei X, Qin Z, Huang J, Assam PN, Maes A, Siddiqui S, Martin UJ, Reisner C. Efficacy And Safety Of Glycopyrrolate/Formoterol Fumarate Metered Dose Inhaler (GFF MDI) Formulated Using Co-Suspension Delivery Technology In Chinese Patients With COPD. Int J Chron Obstruct Pulmon Dis. 2020; 15:43-56.