Epidemiology of community-acquired pneumonia in adults: a population-based study
J Almirall, I Bolibar, J Vidal, G Sauca, P Coll, B Niklasson, M Bartolome, X Balanzo
European Respiratory Journal 2000 15: 757-763; DOI: 10.1034/j.1399-3003.2000.15d21.x