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Mendes de Leon CF, Beckett LA, Fillenbaum GG, Brock DB, Branch LG, Evans DA, Berkman LF.Mendes de Leon CF, et al. Among authors: berkman lf.Am J Epidemiol. 1997 Mar 15;145(6):488-97. doi: 10.1093/oxfordjournals.aje.a009136.Am J Epidemiol. 1997.PMID: 9063338