Umeclidinium Plus Vilanterol Versus Placebo, Umeclidinium, or Vilanterol Monotherapies for Chronic Obstructive Pulmonary Disease: A Meta-Analysis of Randomized Controlled Trials.

Umeclidinium Plus Vilanterol Versus Placebo, Umeclidinium, or Vilanterol Monotherapies for Chronic Obstructive Pulmonary Disease: A Meta-Analysis of Randomized Controlled Trials.