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Spears M, Weir CJ, Smith AD, McSharry C, Chaudhuri R, Johnson M, Cameron E, Thomson NC.Spears M, et al. Among authors: thomson nc.Respir Med. 2011 Dec;105(12):1823-30. doi: 10.1016/j.rmed.2011.06.014. Epub 2011 Aug 12.Respir Med. 2011.PMID: 21840187Free article.Clinical Trial.