The 6-min walk distance in healthy subjects: reference standards from seven countries.
Casanova C, Celli BR, Barria P, Casas A, Cote C, de Torres JP, Jardim J, Lopez MV, Marin JM, Montes de Oca M, Pinto-Plata V, Aguirre-Jaime A. The 6-min walk distance in healthy subjects: reference standards from seven countries. Eur Respir J. 2011 Jan; 37(1):150-6.