Han MK, Wise R, Mumford J, Sciurba F, Criner GJ, Curtis JL, Murray S, Sternberg A, Weinman G, Kazerooni E, Fishman AP, Make B, Hoffman EA, Mosenifar Z, Martinez FJ. Prevalence and clinical correlates of bronchoreversibility in severe emphysema. Eur Respir J. 2010 May; 35(5):1048-56.