110，Paech M．New epidural techniques for labour analgesia:patient-controlled epidural analgesia and combined spinalepidural analgesia．Baillieres Clin Obstet Gynaecol， 1998，12∶377-395．
211，Sia AT，Chong JL．Epidural 0.2％ ropivacaine for labour analge:parturient-controlled or continuous infusion？Anaesth Intensive Care，1999，27∶154-158．
312，Price C，Lafreniere L，Brosnan C，et al．Regional analgesia in early active labour:combined spinal epidural vs epidural．Anaethesia， 1998，53∶951-955．
413，Burnstein R，Buckland R，Picket JA，et al．A survey of epidural analgesia for labour in the United Kingdom．Anaesthesia，1999，54∶634-640．
514，Dresner M，Bamber J，Calow C，et al．Comparison of low-dose epidural with combined spinal-epidural analgesia for labour．Br J Anaesthesia，1999，83∶756-760．
615，Van de Velde M，Mignolet K，Vandermeersch E，et al．Prospective，randomized comparison of epidural and combined spinal epidural analgesia during labor．Acta Anaesthesiol Belg，1999，50∶129-136．
71，Dawson-Basoa M，Gintzler AR．Gestational and ovarian sex steroid antinocieption:synergy between spinal kappa and delta opioid systems．Brain Res，1998，794∶61-67．
82，Dawson-Basoa M，Gintzler AR．Involvement of apinal cord delta opiate receptors in the antinociception of gestation and its hormonal simulation．Brain Res，1997，757∶37-42．
