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San Pedro A, Souza-Santos R, Sabroza PC, Oliveira RM.San Pedro A, et al.Cad Saude Publica. 2009 Sep;25(9):1937-46. doi: 10.1590/s0102-311x2009000900008.Cad Saude Publica. 2009.PMID: 19750381Free article.Portuguese.