1. D. C. Blood, J. A. Henderson, and O. M. Radostits (1979 )-Veterinary Medicine , 5th edn , Bailliere, London. p1029 .
2. Foreign Body Obstruction of the Small Colon in Six Horses
3. S. I. Schwartz, E. H. Storer, and S. I. Schwartz (1974 )-In Principles of Surgery , 2nd edn , McGraw-Hill Book Co., New York, vol II , p969 .