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Liu WH, Thorp TA, Graham SG, Aitkenhead AR.Liu WH, et al. Among authors: aitkenhead ar.Anaesthesia. 1991 Jun;46(6):435-7. doi: 10.1111/j.1365-2044.1991.tb11677.x.Anaesthesia. 1991.PMID: 2048657Free article.