A comparison of epidural analgesia provided by Bupivacaine plus Pethidine, Bupivacaine plus Morphine, or Bupivacaine plus Morphine plus Midazolam for lower limb orthopaedic surgery. J. Kathmandu Med. Coll. 2014;2(3):117-121. doi:10.3126/jkmc.v2i3.9961