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Brown AP, Randall SM, Ferrante AM, Semmens JB, Boyd JH.Brown AP, et al. Among authors: semmens jb.BMC Med Res Methodol. 2017 Jul 10;17(1):95. doi: 10.1186/s12874-017-0370-0.BMC Med Res Methodol. 2017.PMID: 28693507Free PMC article.