Physiological responses to the 6-min walk test in patients with chronic obstructive pulmonary disease
T. Troosters, J. Vilaro, R. Rabinovich, A. Casas, J.A. Barberà, R. Rodriguez-Roisin, J. Roca
European Respiratory Journal 2002 20: 564-569; DOI: 10.1183/09031936.02.02092001