00414nas a2200157   4500000000100000000000100001008004100002100001700043700001400060700001500074700001300089245012200102300001200224490000600236022001400242       2014                            d1 aH. Mullerova1 aA. Shukla1 aA. Hawkins1 aJ. Quint00aRisk factors for acute exacerbations of COPD in a primary care population: a retrospective observational cohort study  ae0061710 v4  a2044-6055