Comparison of Inhaled Long-Acting {beta}-Agonist and Anticholinergic Effectiveness in Older Patients With Chronic Obstructive Pulmonary Disease: A Cohort Study.
Comparison of Inhaled Long-Acting {beta}-Agonist and Anticholinergic Effectiveness in Older Patients With Chronic Obstructive Pulmonary Disease: A Cohort Study.