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Wolff RF, Bala MM, Westwood M, Kessels AG, Kleijnen J.Wolff RF, et al.Swiss Med Wkly. 2010 May 29;140(21-22):297-306. doi: 10.4414/smw.2010.12995.Swiss Med Wkly. 2010.PMID: 20458651Free article.Review.