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Hanf M, Nacher M, Guihenneuc C, Tubert-Bitter P, Chavance M.Hanf M, et al. Among authors: chavance m.BMJ. 2013 Nov 8;347:f6427. doi: 10.1136/bmj.f6427.BMJ. 2013.PMID: 24212105Free PMC article.