Dr. Hira Prasad Singh, Dr. Vinod Kumar. CORRELATION OF PREOPERATIVE ULTRASONOGRAPHIC GALLBLADDER WALL THICKNESS WITH OPERATIVE DIFFICULTY DURING CHOLECYSTECTOMY: AN OBSERVATIONAL STUDY AT A TERTIARY CARE HOSPITAL IN BIHAR. J Popl Ther Clin Pharmacol. 2006;13(1):11-18. doi:10.69980/r45cct79