1. LattoJP&VaughanRS eds.Difficulties in Tracheal Intubation 2nd edn. London: WB Saunders 1997.
2. BenumofJL. Airway Management:Principles and Practice. St Louis Missouri: Mosby Year Book Inc. 1996.
3. Body posture during simulated tracheal intubation;Matthews AJ;British Journal of Anaesthesia,1997