1. Chronic obstructive pulmonary disease in non-smokers
Duncan G Fullerton, Stephen B Gordon, Peter M Calverley 
The Lancet 
Volume 374, Issue 9706, Pages (December 2009)
DOI: /S (09)
Copyright © 2009 Elsevier Ltd Terms and Conditions

2. Figure Rural home in Chikwawa, southern Malawi
Typical house construction: grass thatched roof, small space for windows, smoke marks clearly visible from cooking that takes place on the verandah or indoors.
The Lancet  , DOI: ( /S (09) )
Copyright © 2009 Elsevier Ltd Terms and Conditions