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Ridd M, Purdy S.Ridd M, et al. Among authors: purdy s.BMJ. 2009 Aug 25;339:b2997. doi: 10.1136/bmj.b2997.BMJ. 2009.PMID: 19706651No abstract available.
Ridd M, Purdy S.Ridd M, et al. Among authors: purdy s.Praxis (Bern 1994). 2010 Jan 20;99(2):123-5. doi: 10.1024/1661-8157/a000019.Praxis (Bern 1994). 2010.PMID: 20087832Review.German.No abstract available.