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1 From the World Health Organization, Geneva (N.B., A.K., C.D.), and the Institute of Social and Preventive Medicine, University of Bern, Bern (F.K., M.R., N.L.) - both in Switzerland; and the Pan American Health Organization, Washington, DC (M.A., S.A., M.E.).
1 From the World Health Organization, Geneva (N.B., A.K., C.D.), and the Institute of Social and Preventive Medicine, University of Bern, Bern (F.K., M.R., N.L.) - both in Switzerland; and the Pan American Health Organization, Washington, DC (M.A., S.A., M.E.).