Indacaterol-Glycopyrronium versus Salmeterol-Fluticasone for COPD.
N Engl J Med. 2016 Jun 9;374(23):2222-34. doi: 10.1056/NEJMoa1516385. Epub 2016 May 15. N Engl J Med. 2016. PMID: 27181606 Free article. Clinical Trial.