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2. A Short History of Anaesthesia: The first 150 years;Rushman,1996
3. Spinal anaesthesia in obstetrics;Morgan;Can J Anaesth,1995
4. Combined spinal epidural technique;Rawal;Reg Anesth,1997
5. How anesthesiologists practice obstetric anesthesia;Plumer;Reg Anesth,1996