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Hopman WM, Garvey N, Olajos-Clow J, White-Markham A, Lougheed MD.Hopman WM, et al.Can Respir J. 2004 May-Jun;11(4):291-7. doi: 10.1155/2004/847628.Can Respir J. 2004.PMID: 15254611Free article.