An international survey of chronic obstructive pulmonary disease in young adults according to GOLD stages
R de Marco, S Accordini, I Cerveri, A Corsico, J Sunyer, F Neukirch, N Künzli, B Leynaert, C Janson, T Gislason, P Vermeire, C Svanes, J M Anto, P Burney
Thorax Feb 2004, 59 (2) 120-125; DOI: 10.1136/thorax.2003.011163