1. WilfredTrotter: “Observation and Experiment and Their Use in the Medical Sciences” The British Medical Journal July 26 1930 page129.
2. W. H. A.Jacobson: “The Operations of Surgery” 1891 pages849to 860.
3. D. P. D.Wilkie: “Ætiology of Gall Bladder Infections” The British Medical Journal February 1 1930 page196.
4. Abnormalities of the Right Hepatic, Cystic and Gastro‐Duodenal Arteries, and the Bile Ducts;Flint E. R.;The British Journal of Surgery,1922
5. LudwigAschoff: “Lectures in Pathology” 1924 page217.