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O Flaherty M, Flores-Mateo G, Nnoaham K, Lloyd-Williams F, Capewell S.O Flaherty M, et al.Bull World Health Organ. 2012 Jul 1;90(7):522-31. doi: 10.2471/BLT.11.092643. Epub 2012 Apr 12.Bull World Health Organ. 2012.PMID: 22807598Free PMC article.