1. Long duration of subarachnoid anesthesia with continuous epidural blocks;Curelaru;Prakt Anaesth,1979
2. Epidural and subarachnoidal analgesia for elective cesearean section;Brownridge;Anaesthesia,1981
3. Combined subarachnoid and epidural techniques;Coates;Anaesthesia,1982
4. Another single space technique for orthopedic surgery;Mumtaz;Anaesthesia,1982
5. Combined Spinal Epidural versus epidural analgesia in labour;Simmons;Cochrane Database of Systemic Reviews,2012