Long-acting muscarinic antagonists vs. long-acting β2 agonists in COPD exacerbations: a systematic review and meta-analysis
Israel Silva Maia1, Mariângela Pimentel Pincelli1, Victor Figueiredo Leite2, João Amadera3, Anna Maria Buehler4
DOI: http://dx.doi.org/10.1590/S1806-37562016000000287