1[3]Kissin I.Preemptive Analgesia:why its effect is not always obvious[J].Anesthesiology,1996,84(5):1015-1019.
2[5]Jakobsson J,Rane K.Anaesthesia for short outpatient procedures.A comparison between thiopentone and propofol in combination with fentanyl or alfentanil[J].Acta Anaesthesiol scand,1995,39(4):503 -507.