Figure 1From: Systematic review of the epidemiological evidence comparing lung cancer risk in smokers of mentholated and unmentholated cigarettes Flow diagram for literature search. The diagram shows the number of papers identified at various stages of the search, and the numbers rejected and accepted. (Note that in the last box, showing the total number of titles as abstracts screened, the figure of 2172 double-counts papers identified in more than one search.)Back to article page