1. 1. Tandon R.Diseases of Gall Bladder and Biliary Tract. In:API Textbook of Medicine, Shah SN, ed. 9th ed. Mumbai:API Publications;2012 Apr. p.911.
2. 2. Park K. Man and medicine towards health for all. In:Park's Text book of preventiveand socialmedicine. 17thed. New Delhi:Banarasi Das Publications;2002 Nov. p.1-10.
3. 3. Karan JA, Rose GJ. Cholelithiasis and cholecystectomy. In:Maingot's abdominal operations, Zynnel MJ, Schwartz SI, Ellis H, eds. 10th ed. New York:McGraw-Hill Publications;2001. p.1717-38.
4. Incidence of gallstones in a Danish population;KH;Gastroenterology,1991
5. 5. Cuschieri A. Disorder of the biliary tract. In:Textbook of surgery. 4th ed. Philadelphia:Arnold Publication;2002. p.375-453.