1. Sputum colour reported by patients is not a reliable marker of the presence of bacteria in acute exacerbations of chronic obstructive pulmonary disease 
J.M.A. Daniels, C.S. de Graaff, F. Vlaspolder, D. Snijders, H.M. Jansen, W.G. Boersma 
Clinical Microbiology and Infection 
Volume 16, Issue 6, Pages (June 2010)
DOI: /j x
Copyright © 2010 European Society of Clinical Infectious Diseases Terms and Conditions

2. FIG. 1
Mean log bacterial load (± standard error of the mean and p-value) of the primary pathogen for mucoid and purulent sputum as reported by patients (a) and as assessed with a sputum colour chart (b) [4].
Clinical Microbiology and Infection  , DOI: ( /j x)
Copyright © 2010 European Society of Clinical Infectious Diseases Terms and Conditions

3. FIG. 2
Mean serum C-reactive protein (± standard error of the mean and p-value) in exacerbations with mucoid and purulent sputum as reported by patients (a) and as assessed with a sputum colour chart (b) [4].
Clinical Microbiology and Infection  , DOI: ( /j x)
Copyright © 2010 European Society of Clinical Infectious Diseases Terms and Conditions