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Parra DC, McKenzie TL, Ribeiro IC, Ferreira Hino AA, Dreisinger M, Coniglio K, Munk M, Brownson RC, Pratt M, Hoehner CM, Simoes EJ.
Parra DC, et al.
Am J Public Health. 2010 Aug;100(8):1420-6. doi: 10.2105/AJPH.2009.181230. Epub 2010 Jun 17.
Am J Public Health. 2010.
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Free PMC article.