9Anderson D, Macnee W. Targeted treatment in COPD: a multi- system approach for a multi-system disease. Int J Chron Obstruct Pulmon Dis, 2009, 4: 321-335.
10Mahler DA, Criner GJ. Assessment tools for chronic obstructive pulmonary disease: do newer metrics allow for disease modification? Proc Am Thorac Soc, 2007, 4 : 507-511.