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Manzini G, Ettrich TJ, Kremer M, Kornmann M, Henne-Bruns D, Eikema DA, Schlattmann P, de Wreede LC.Manzini G, et al.BMC Med Res Methodol. 2018 Feb 13;18(1):23. doi: 10.1186/s12874-018-0476-z.BMC Med Res Methodol. 2018.PMID: 29439652Free PMC article.