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2. Assistance for the Anaesthetist. Association of Anaesthetists of Great Britain & Ireland,1988
3. The Anaesthesia Team. Association of Anaesthetists of Great Britain & Ireland,1998
4. Anesthesia providers, patient outcomes, and costs;Abenstein;Anesthesia and Analgesia,1996
5. Anesthesiologist direction and patient outcomes;Silber;Anesthesiology,2000