1. 1. Atkinson RS, Rushnman GB, Davies. Regional Anaesthesia in Lee's synopsis of anaesthesia. 11th ed. Butterworth Heinnman publisher 1993;642-648.
2. 2. David L, Brown B, Raymond Fink. The History of Neural Blockade and Pain Management. Michael J Cousins, Phillip O, Bridenbaugh's neural blockade in clinical anesthesia and management of pain. 3r ed. Lippincott-Raven publisher; 1998;3-25.
3. 3. Downing JW, Leary WP, White ES. Buprenorphine: A new potent long acting synthetic analgesic, Comparison with morphine.
4. Br J Anaesth 1977;49:251-255.
5. 4. Young WS, Wamsley JK, Zarbin MA, et al. Opioid receptors undergo axonal flow.