Thoracic epidural for post-thoracotomy and thoracomyoplasty pain: a comparative study of three concentrations of fentanyl with plain ropivacaine - Chaudhary, Ajay Kr; Singh, Dinesh; Bogra, Jai Shri; Saxena, Sulekha; Chandra, Girish; Bhusan, Shashi; Singh, Prithvi Kr (Anaesthesia, Pain & Intensive Care, 2019)